diff --git a/README.md b/README.md
index b42df6d..063cd1a 100644
--- a/README.md
+++ b/README.md
@@ -97,9 +97,9 @@ touch main.c
 #include "libcproject/libcproject.h"
 
 int main() {
-  char* string = "Hello, world!";
-  printf("%s\n", string);
-  printf("string_length = %ld\n", string_get_length(string)); // `string_get_length` is a function from `libcproject`
+  string string_value = "Hello, world!"; // `string` is a typedef from `libcproject`
+  printf("%s\n", string_value);
+  printf("string_length = %ld\n", string_get_length(string_value)); // `string_get_length` is a function from `libcproject`
   return EXIT_SUCCESS;
 }
 ```
diff --git a/lib/character.c b/lib/character.c
index ea22e8e..1e79e93 100644
--- a/lib/character.c
+++ b/lib/character.c
@@ -1,17 +1,17 @@
 #include "character.h"
 
-void character_append(char* string, const char character) {
-  size_t length = string_get_length(string);
-  character_append_at(string, character, length);
+void character_append(string string_value, const char character) {
+  size_t length = string_get_length(string_value);
+  character_append_at(string_value, character, length);
 }
 
-void character_append_at(char* string, const char character, const size_t index) {
-  size_t length = string_get_length(string);
+void character_append_at(string string_value, const char character, const size_t index) {
+  size_t length = string_get_length(string_value);
   for (size_t index_string = length; index_string > index; index_string--) {
-    string[index_string] = string[index_string - 1];
+    string_value[index_string] = string_value[index_string - 1];
   }
-  string[index] = character;
-  string[length + 1] = '\0';
+  string_value[index] = character;
+  string_value[length + 1] = '\0';
 }
 
 char character_to_upper(const char character) {
diff --git a/lib/character.h b/lib/character.h
index 14cf7ce..679bbfc 100644
--- a/lib/character.h
+++ b/lib/character.h
@@ -14,7 +14,7 @@
  * @param character
  * @since v1.0.0
  */
-void character_append(char* string, char character);
+void character_append(string string_value, char character);
 
 /**
  * @brief Append a character to a string at a specific index, assuming string points to an array with enough space.
@@ -24,7 +24,7 @@ void character_append(char* string, char character);
  * @param index
  * @since v1.0.0
  */
-void character_append_at(char* string, const char character, const size_t index);
+void character_append_at(string string_value, const char character, const size_t index);
 
 /**
  * @brief Converts the character to uppercase.
diff --git a/lib/convert.c b/lib/convert.c
index 38155a8..38e3a50 100644
--- a/lib/convert.c
+++ b/lib/convert.c
@@ -1,7 +1,7 @@
 #include "convert.h"
 
-char* convert_character_to_string(const char character) {
-  char* string = malloc(sizeof(char*) * 2);
+string convert_character_to_string(const char character) {
+  string string = malloc(sizeof(string) * 2);
   if (string == NULL) {
     exit(EXIT_FAILURE);
   }
@@ -17,42 +17,42 @@ char convert_digit_to_character(const char digit) {
   return digit + '0';
 }
 
-long long convert_string_to_number(const char* string) {
-  bool is_negative = string[0] == '-';
+long long convert_string_to_number(const string string_value) {
+  bool is_negative = string_value[0] == '-';
   long long integer = 0;
-  size_t length = string_get_length(string);
+  size_t length = string_get_length(string_value);
   for (size_t index = is_negative ? 1 : 0; index < length; index++) {
-    integer = integer * 10 + convert_character_to_digit(string[index]);
+    integer = integer * 10 + convert_character_to_digit(string_value[index]);
   }
   return is_negative ? integer * -1 : integer;
 }
 
-char* convert_number_to_string(const long long integer) {
+string convert_number_to_string(const long long integer) {
   if (integer == 0) {
     return convert_character_to_string('0');
   }
   bool is_negative = integer < 0;
   size_t length = 1;
-  char* string = malloc(sizeof(char*) * length);
-  if (string == NULL) {
+  string string_value = malloc(sizeof(string) * length);
+  if (string_value == NULL) {
     exit(EXIT_FAILURE);
   }
   long long current = mathematics_absolute_value(integer);
   while (current != 0) {
-    character_append(string, convert_digit_to_character(current % 10));
+    character_append(string_value, convert_digit_to_character(current % 10));
     current = current / 10;
     length++;
-    string = realloc(string, sizeof(char*) * length);
+    string_value = realloc(string_value, sizeof(string) * length);
   }
   if (is_negative) {
-    character_append(string, '-');
+    character_append(string_value, '-');
     length++;
-    string = realloc(string, sizeof(char*) * length);
+    string_value = realloc(string_value, sizeof(string) * length);
   }
-  return string_reverse(string);
+  return string_reverse(string_value);
 }
 
-char* convert_number_from_base_10_to_base(unsigned long long number, unsigned int base) {
+string convert_number_from_base_10_to_base(unsigned long long number, unsigned int base) {
   if (number == 0) {
     return "0";
   }
@@ -63,7 +63,7 @@ char* convert_number_from_base_10_to_base(unsigned long long number, unsigned in
     number = number / base;
     index++;
   }
-  char* result = malloc(sizeof(char) * (index + 1));
+  string result = malloc(sizeof(string) * (index + 1));
   int index_result = 0;
   for (int iteration = index - 1; iteration >= 0; iteration--) {
     int remainder = remainders[iteration];
@@ -77,7 +77,7 @@ char* convert_number_from_base_10_to_base(unsigned long long number, unsigned in
   return result;
 }
 
-int convert_number_from_base_to_base_10(char* number, unsigned int base) {
+int convert_number_from_base_to_base_10(string number, unsigned int base) {
   int length = string_get_length(number);
   int exponent = length - 1;
   int result = 0;
@@ -96,6 +96,6 @@ int convert_number_from_base_to_base_10(char* number, unsigned int base) {
   return result;
 }
 
-char* convert_number_from_base_to_another(char* number, int base_from, int base_target) {
+string convert_number_from_base_to_another(string number, int base_from, int base_target) {
   return convert_number_from_base_10_to_base(convert_number_from_base_to_base_10(number, base_from), base_target);
 }
diff --git a/lib/convert.h b/lib/convert.h
index 251ac25..761d830 100644
--- a/lib/convert.h
+++ b/lib/convert.h
@@ -15,13 +15,12 @@
  * @param character
  * @since v1.0.0
  */
-char* convert_character_to_string(const char character);
+string convert_character_to_string(const char character);
 
 /**
  * @brief Convert a character to a digit.
  *
  * @param character
- * @return char
  * @since v1.0.0
  */
 char convert_character_to_digit(const char character);
@@ -30,7 +29,6 @@ char convert_character_to_digit(const char character);
  * @brief Convert a digit to a character.
  *
  * @param digit
- * @return char
  * @since v1.0.0
  */
 char convert_digit_to_character(const char digit);
@@ -39,39 +37,35 @@ char convert_digit_to_character(const char digit);
  * @brief Convert a string to a number.
  *
  * @param string
- * @return long long
  * @since v1.0.0
  */
-long long convert_string_to_number(const char* string);
+long long convert_string_to_number(const string string_value);
 
 /**
  * @brief Convert a number to a string.
  *
  * @param integer
- * @return char*
  * @since v1.0.0
  */
-char* convert_number_to_string(const long long integer);
+string convert_number_to_string(const long long integer);
 
 /**
  * @brief Convert a number (base 10) to a string with a specific base.
  *
  * @param number
  * @param base
- * @return char*
  * @since v1.0.0
  */
-char* convert_number_from_base_10_to_base(unsigned long long number, unsigned int base);
+string convert_number_from_base_10_to_base(unsigned long long number, unsigned int base);
 
 /**
  * @brief Convert a number with a specific base to a number base 10.
  *
  * @param number
  * @param base
- * @return int
  * @since v1.0.0
  */
-int convert_number_from_base_to_base_10(char* number, unsigned int base);
+int convert_number_from_base_to_base_10(string number, unsigned int base);
 
 /**
  * @brief Convert a number with a specific base to a number of specific base.
@@ -79,9 +73,8 @@ int convert_number_from_base_to_base_10(char* number, unsigned int base);
  * @param number
  * @param base_from
  * @param base_target
- * @return char*
  * @since v1.0.0
  */
-char* convert_number_from_base_to_another(char* number, int base_from, int base_target);
+string convert_number_from_base_to_another(string number, int base_from, int base_target);
 
 #endif
diff --git a/lib/filesystem.c b/lib/filesystem.c
index 04abbed..37436f1 100644
--- a/lib/filesystem.c
+++ b/lib/filesystem.c
@@ -1,6 +1,6 @@
 #include "filesystem.h"
 
-int filesystem_read(char *path, byte **file_content, off_t *file_size) {
+int filesystem_read(string path, byte **file_content, off_t *file_size) {
   int file_descriptor = open(path, O_RDONLY);
   if (file_descriptor == -1) {
     return -1;
@@ -15,7 +15,7 @@ int filesystem_read(char *path, byte **file_content, off_t *file_size) {
   return 0;
 }
 
-int filesystem_write(char *path, byte *file_content, off_t file_size) {
+int filesystem_write(string path, byte *file_content, off_t file_size) {
   int file_descriptor = open(path, O_WRONLY | O_CREAT | O_TRUNC, 0644);
   if (file_descriptor == -1) {
     return -1;
@@ -27,7 +27,7 @@ int filesystem_write(char *path, byte *file_content, off_t file_size) {
   return 0;
 }
 
-char *filesystem_get_mimetype(char *path) {
+char *filesystem_get_mimetype(string path) {
   if (string_ends_with(path, ".html")) {
     return "text/html";
   }
diff --git a/lib/filesystem.h b/lib/filesystem.h
index 824a8c6..f8a3d3e 100644
--- a/lib/filesystem.h
+++ b/lib/filesystem.h
@@ -26,7 +26,7 @@ typedef uint8_t byte;
  * @retval 0 for success.
  * @since v1.0.0
  */
-int filesystem_read(char *path, byte **file_content, off_t *file_size);
+int filesystem_read(string path, byte **file_content, off_t *file_size);
 
 /**
  * @brief Write the content to a file.
@@ -39,15 +39,14 @@ int filesystem_read(char *path, byte **file_content, off_t *file_size);
  * @retval 0 for success.
  * @since v1.0.0
  */
-int filesystem_write(char *path, byte *file_content, off_t file_size);
+int filesystem_write(string path, byte *file_content, off_t file_size);
 
 /**
  * @brief Get the mimetype of a file.
  *
  * @param path
- * @return char*
  * @since v1.0.0
  */
-char *filesystem_get_mimetype(char *path);
+string filesystem_get_mimetype(string path);
 
 #endif
diff --git a/lib/string.c b/lib/string.c
index d610caf..15d5f3f 100644
--- a/lib/string.c
+++ b/lib/string.c
@@ -1,118 +1,118 @@
 #include "string.h"
 
-size_t string_get_length(const char* string) {
+size_t string_get_length(const string string_value) {
   size_t length = 0;
-  while (string[length] != '\0') {
+  while (string_value[length] != '\0') {
     length++;
   }
   return length;
 }
 
-char* string_to_uppercase(char* string) {
-  size_t string_length = string_get_length(string);
-  char* result = malloc(sizeof(char*) * string_length);
+string string_to_uppercase(string string_value) {
+  size_t string_length = string_get_length(string_value);
+  string result = malloc(sizeof(string) * string_length);
   if (result == NULL) {
     exit(EXIT_FAILURE);
   }
   for (size_t index = 0; index < string_length; index++) {
-    character_append(result, character_to_upper(string[index]));
+    character_append(result, character_to_upper(string_value[index]));
   }
   return result;
 }
 
-char* string_to_lowercase(char* string) {
-  size_t string_length = string_get_length(string);
-  char* result = malloc(sizeof(char*) * string_length);
+string string_to_lowercase(string string_value) {
+  size_t string_length = string_get_length(string_value);
+  string result = malloc(sizeof(string) * string_length);
   if (result == NULL) {
     exit(EXIT_FAILURE);
   }
   for (size_t index = 0; index < string_length; index++) {
-    character_append(result, character_to_lower(string[index]));
+    character_append(result, character_to_lower(string_value[index]));
   }
   return result;
 }
 
-char* string_replace(char* string, char search, char replace) {
-  size_t string_length = string_get_length(string);
-  char* result = malloc(sizeof(char*) * string_length);
+string string_replace(string string_value, char search, char replace) {
+  size_t string_length = string_get_length(string_value);
+  string result = malloc(sizeof(string) * string_length);
   if (result == NULL) {
     exit(EXIT_FAILURE);
   }
   for (size_t index = 0; index < string_length; index++) {
-    bool is_search_value = search == string[index];
+    bool is_search_value = search == string_value[index];
     if (is_search_value) {
       character_append(result, replace);
     } else {
-      character_append(result, string[index]);
+      character_append(result, string_value[index]);
     }
   }
   return result;
 }
 
-char* string_trim_start(char* string) {
-  size_t string_length = string_get_length(string);
-  char* result = malloc(sizeof(char*) * string_length);
+string string_trim_start(string string_value) {
+  size_t string_length = string_get_length(string_value);
+  string result = malloc(sizeof(string) * string_length);
   if (result == NULL) {
     exit(EXIT_FAILURE);
   }
   size_t index_space = 0;
-  while (string[index_space] == ' ') {
+  while (string_value[index_space] == ' ') {
     index_space++;
   }
   for (size_t index = index_space; index < string_length; index++) {
-    character_append(result, string[index]);
+    character_append(result, string_value[index]);
   }
   return result;
 }
 
-char* string_trim_end(char* string) {
-  size_t string_length = string_get_length(string);
-  char* result = malloc(sizeof(char*) * string_length);
+string string_trim_end(string string_value) {
+  size_t string_length = string_get_length(string_value);
+  string result = malloc(sizeof(string) * string_length);
   if (result == NULL) {
     exit(EXIT_FAILURE);
   }
   size_t index_space = string_length - 1;
-  while (string[index_space] == ' ') {
+  while (string_value[index_space] == ' ') {
     index_space--;
   }
   for (size_t index = 0; index < index_space + 1; index++) {
-    character_append(result, string[index]);
+    character_append(result, string_value[index]);
   }
   return result;
 }
 
-char* string_trim(char* string) {
-  char* result = string_trim_start(string);
+string string_trim(string string_value) {
+  string result = string_trim_start(string_value);
   result = string_trim_end(result);
   return result;
 }
 
-char* string_copy(const char* string) {
-  return string_substring(string, 0, string_get_length(string));
+string string_copy(const string string_value) {
+  return string_substring(string_value, 0, string_get_length(string_value));
 }
 
-char* string_capitalize(char* string) {
-  size_t string_length = string_get_length(string);
-  char* result = malloc(sizeof(char*) * string_length);
+string string_capitalize(string string_value) {
+  size_t string_length = string_get_length(string_value);
+  string result = malloc(sizeof(string) * string_length);
   if (result == NULL) {
     exit(EXIT_FAILURE);
   }
   for (size_t index = 0; index < string_length; index++) {
     bool is_first_character = index == 0;
     if (is_first_character) {
-      character_append(result, character_to_upper(string[index]));
+      character_append(result, character_to_upper(string_value[index]));
     } else {
-      character_append(result, string[index]);
+      character_append(result, string_value[index]);
     }
   }
   return result;
 }
 
-size_t string_total_occurrences_of_character(char* string, char character) {
+size_t string_total_occurrences_of_character(string string_value, char character) {
   size_t result = 0;
-  size_t string_length = string_get_length(string);
+  size_t string_length = string_get_length(string_value);
   for (size_t index = 0; index < string_length; index++) {
-    char current_character = string[index];
+    char current_character = string_value[index];
     if (current_character == character) {
       result += 1;
     }
@@ -120,21 +120,21 @@ size_t string_total_occurrences_of_character(char* string, char character) {
   return result;
 }
 
-char* string_reverse(const char* string) {
-  size_t string_length = string_get_length(string);
+string string_reverse(const string string_value) {
+  size_t string_length = string_get_length(string_value);
   size_t index = 0;
-  char* result = malloc(sizeof(char*) * string_length);
+  string result = malloc(sizeof(string) * string_length);
   if (result == NULL) {
     exit(EXIT_FAILURE);
   }
   for (index = string_length - 1; index > 0; index--) {
-    character_append(result, string[index]);
+    character_append(result, string_value[index]);
   }
-  character_append(result, string[index]);
+  character_append(result, string_value[index]);
   return result;
 }
 
-bool string_equals(const char* string1, const char* string2) {
+bool string_equals(const string string1, const string string2) {
   size_t string1_length = string_get_length(string1);
   size_t string2_length = string_get_length(string2);
   bool is_equal = string1_length == string2_length;
@@ -146,11 +146,11 @@ bool string_equals(const char* string1, const char* string2) {
   return is_equal;
 }
 
-bool string_get_is_integer(const char* string) {
+bool string_get_is_integer(const string string_value) {
   size_t index = 0;
-  size_t string_length = string_get_length(string);
+  size_t string_length = string_get_length(string_value);
   bool is_integer = string_length >= 1;
-  if (is_integer && string[0] == '-') {
+  if (is_integer && string_value[0] == '-') {
     if (string_length == 1) {
       is_integer = false;
     } else {
@@ -158,7 +158,7 @@ bool string_get_is_integer(const char* string) {
     }
   }
   while (index < string_length && is_integer) {
-    if (!character_get_is_digit(string[index])) {
+    if (!character_get_is_digit(string_value[index])) {
       is_integer = false;
     }
     index++;
@@ -166,28 +166,28 @@ bool string_get_is_integer(const char* string) {
   return is_integer;
 }
 
-char** string_split(const char* string, char separator, size_t* result_size) {
-  size_t string_length = string_get_length(string);
+string* string_split(const string string_value, char separator, size_t* result_size) {
+  size_t string_length = string_get_length(string_value);
   size_t index_string = 0;
   size_t index_current = 0;
   size_t index_result = 0;
-  char* current = malloc(sizeof(char*) * string_length);
-  char** result = malloc(sizeof(char**) * index_result);
+  string current = malloc(sizeof(string) * string_length);
+  string* result = malloc(sizeof(string*) * index_result);
   if (result == NULL || current == NULL) {
     exit(EXIT_FAILURE);
   }
   while (index_string < string_length) {
-    if (string[index_string] == separator) {
+    if (string_value[index_string] == separator) {
       result[index_result] = string_copy(current);
       index_result++;
-      result = realloc(result, sizeof(char*) * index_result);
+      result = realloc(result, sizeof(string_value) * index_result);
       if (result == NULL) {
         exit(EXIT_FAILURE);
       }
       index_current = 0;
       current = string_copy("");
     } else {
-      character_append(current, string[index_string]);
+      character_append(current, string_value[index_string]);
       index_current++;
     }
     index_string++;
@@ -198,36 +198,36 @@ char** string_split(const char* string, char separator, size_t* result_size) {
   return result;
 }
 
-char* string_join(char** array, const char separator, size_t array_length) {
+string string_join(string* array, const char separator, size_t array_length) {
   size_t string_length = array_length;
-  char* string = malloc(sizeof(char*) * string_length);
-  if (string == NULL) {
+  string string_value = malloc(sizeof(string_value) * string_length);
+  if (string_value == NULL) {
     exit(EXIT_FAILURE);
   }
   for (size_t index_array = 0; index_array < array_length; index_array++) {
-    char* substring = array[index_array];
+    string substring = array[index_array];
     size_t substring_length = string_get_length(substring);
     string_length += substring_length;
-    string = realloc(string, sizeof(char*) * string_length);
-    if (string == NULL) {
+    string_value = realloc(string_value, sizeof(string_value) * string_length);
+    if (string_value == NULL) {
       exit(EXIT_FAILURE);
     }
     for (size_t index_substring = 0; index_substring < substring_length; index_substring++) {
-      character_append(string, substring[index_substring]);
+      character_append(string_value, substring[index_substring]);
     }
     bool is_last_character = index_array == (array_length - 1);
     if (!is_last_character) {
-      character_append(string, separator);
+      character_append(string_value, separator);
     }
   }
-  return string;
+  return string_value;
 }
 
-char* string_concatenate(char* string1, char* string2) {
+string string_concatenate(string string1, string string2) {
   size_t string1_length = string_get_length(string1);
   size_t string2_length = string_get_length(string2);
   size_t result_length = string1_length + string2_length;
-  char* result = malloc(sizeof(char*) * result_length);
+  string result = malloc(sizeof(string) * result_length);
   if (result == NULL) {
     exit(EXIT_FAILURE);
   }
@@ -240,13 +240,13 @@ char* string_concatenate(char* string1, char* string2) {
   return result;
 }
 
-bool string_get_has_unique_characters(const char* string) {
+bool string_get_has_unique_characters(const string string_value) {
   bool has_unique = true;
-  size_t string_length = string_get_length(string);
+  size_t string_length = string_get_length(string_value);
   struct dictionary* characters_already_seen = dictionary_initialization();
   for (size_t index = 0; index < string_length && has_unique; index++) {
-    char character = string[index];
-    char* key = convert_character_to_string(character);
+    char character = string_value[index];
+    string key = convert_character_to_string(character);
     if (dictionary_contains_key(characters_already_seen, key)) {
       has_unique = false;
     } else {
@@ -256,23 +256,23 @@ bool string_get_has_unique_characters(const char* string) {
   return has_unique;
 }
 
-char* string_substring(const char* string, size_t index_start, size_t index_end) {
-  size_t string_length = string_get_length(string);
-  char* result = malloc(sizeof(char*) * string_length);
+string string_substring(const string string_value, size_t index_start, size_t index_end) {
+  size_t string_length = string_get_length(string_value);
+  string result = malloc(sizeof(string) * string_length);
   for (size_t index = index_start; index <= index_end; index++) {
-    character_append(result, string[index]);
+    character_append(result, string_value[index]);
   }
   return result;
 }
 
-bool string_get_is_substring(const char* string, const char* substring) {
+bool string_get_is_substring(const string string_value, const string substring) {
   bool is_substring = false;
-  size_t string_length = string_get_length(string);
+  size_t string_length = string_get_length(string_value);
   size_t substring_length = string_get_length(substring);
   for (size_t index_string = 0; index_string < string_length && !is_substring; index_string++) {
     size_t index_substring = 0;
     size_t index_considered = index_string;
-    while (index_substring < substring_length && string[index_considered] == substring[index_substring]) {
+    while (index_substring < substring_length && string_value[index_considered] == substring[index_substring]) {
       index_substring++;
       index_considered++;
     }
@@ -281,14 +281,14 @@ bool string_get_is_substring(const char* string, const char* substring) {
   return is_substring;
 }
 
-char* string_get_formatted_number(const long long number, char* separator) {
-  char* number_string = convert_number_to_string(number);
+string string_get_formatted_number(const long long number, string separator) {
+  string number_string = convert_number_to_string(number);
   bool is_negative = number_string[0] == '-';
   if (is_negative) {
     number_string = string_substring(number_string, 1, string_get_length(number_string));
   }
   size_t number_string_length = string_get_length(number_string);
-  char* result = malloc(sizeof(char*) * number_string_length);
+  string result = malloc(sizeof(string) * number_string_length);
   if (result == NULL) {
     exit(EXIT_FAILURE);
   }
@@ -313,41 +313,41 @@ char* string_get_formatted_number(const long long number, char* separator) {
   return result;
 }
 
-char* string_get_last_occurence_of_character(const char* string, char character) {
-  size_t string_length = string_get_length(string);
-  char* result = malloc(sizeof(char*) * string_length);
+string string_get_last_occurence_of_character(const string string_value, char character) {
+  size_t string_length = string_get_length(string_value);
+  string result = malloc(sizeof(string) * string_length);
   if (result == NULL) {
     exit(EXIT_FAILURE);
   }
   size_t index_result = 0;
   for (size_t index = 0; index < string_length; index++) {
-    if (string[index] == character) {
+    if (string_value[index] == character) {
       index_result = 0;
       result = string_copy("");
     }
-    character_append(result, string[index]);
+    character_append(result, string_value[index]);
     index_result++;
   }
   return result;
 }
 
-bool string_starts_with(const char* string, const char* prefix) {
+bool string_starts_with(const string string_value, const string prefix) {
   bool starts_with = true;
   size_t prefix_length = string_get_length(prefix);
   for (size_t index = 0; index < prefix_length && starts_with; index++) {
-    starts_with = string[index] == prefix[index];
+    starts_with = string_value[index] == prefix[index];
   }
   return starts_with;
 }
 
-bool string_ends_with(const char* string, const char* prefix) {
+bool string_ends_with(const string string_value, const string prefix) {
   bool ends_with = true;
-  size_t string_length = string_get_length(string);
+  size_t string_length = string_get_length(string_value);
   size_t prefix_length = string_get_length(prefix);
   size_t index_string = string_length - 1;
   size_t index_prefix = prefix_length - 1;
   while (index_prefix > 0 && ends_with) {
-    ends_with = string[index_string] == prefix[index_prefix];
+    ends_with = string_value[index_string] == prefix[index_prefix];
     index_string--;
     index_prefix--;
   }
diff --git a/lib/string.h b/lib/string.h
index 9a37cf2..cfdbe5f 100644
--- a/lib/string.h
+++ b/lib/string.h
@@ -9,6 +9,8 @@
 #include "convert.h"
 #include "dictionary.h"
 
+typedef char* string;
+
 /**
  * @brief Return the length of a string (excluding '\0').
  *
@@ -16,25 +18,23 @@
  * @return size_t
  * @since v1.0.0
  */
-size_t string_get_length(const char* string);
+size_t string_get_length(const string string_value);
 
 /**
  * @brief Converts all the alphabetic characters in a string to uppercase.
  *
  * @param string
- * @return char*
  * @since v1.0.0
  */
-char* string_to_uppercase(char* string);
+string string_to_uppercase(string string_value);
 
 /**
  * @brief Converts all the alphabetic characters in a string to lowercase.
  *
  * @param string
- * @return char*
  * @since v1.0.0
  */
-char* string_to_lowercase(char* string);
+string string_to_lowercase(string string_value);
 
 /**
  * @brief Replace all the occurrences of search value into replace value in the string.
@@ -42,55 +42,49 @@ char* string_to_lowercase(char* string);
  * @param string
  * @param search_value A character search value.
  * @param replace_value A character containing the text to replace for match.
- * @return char*
  * @since v1.0.0
  */
-char* string_replace(char* string, char search, char replace);
+string string_replace(string string_value, char search, char replace);
 
 /**
  * @brief Removes all whitespace from the start of a string.
  *
  * @param string
- * @return char*
  * @since v1.0.0
  */
-char* string_trim_start(char* string);
+string string_trim_start(string string_value);
 
 /**
  * @brief Removes all whitespace from the end of a string.
  *
  * @param string
- * @return char*
  * @since v1.0.0
  */
-char* string_trim_end(char* string);
+string string_trim_end(string string_value);
 
 /**
  * @brief Removes all whitespace from the start and end of a string.
  *
  * @param string
- * @return char*
  * @since v1.0.0
  */
-char* string_trim(char* string);
+string string_trim(string string_value);
 
 /**
  * @brief Return the copy of a string.
  *
  * @param string
- * @return char*
  * @since v1.0.0
  */
-char* string_copy(const char* string);
+string string_copy(const string string_value);
 
 /**
  * @brief Capitalizes the string.
  *
  * @param string
- * @return char*
  * @since v1.0.0
  */
-char* string_capitalize(char* string);
+string string_capitalize(string string_value);
 
 /**
  * @brief Returns the total number of occurrences of the given character in the string.
@@ -100,16 +94,15 @@ char* string_capitalize(char* string);
  * @return size_t
  * @since v1.0.0
  */
-size_t string_total_occurrences_of_character(char* string, char character);
+size_t string_total_occurrences_of_character(string string_value, char character);
 
 /**
  * @brief Reverse the characters in an array.
  *
  * @param string
- * @return char*
  * @since v1.0.0
  */
-char* string_reverse(const char* string);
+string string_reverse(const string string_value);
 
 /**
  * @brief Check if two strings are equals.
@@ -119,7 +112,7 @@ char* string_reverse(const char* string);
  * @return true if the strings are equals, false otherwise.
  * @since v1.0.0
  */
-bool string_equals(const char* string1, const char* string2);
+bool string_equals(const string string1, const string string2);
 
 /**
  * @brief Check if the string is a integer.
@@ -128,37 +121,34 @@ bool string_equals(const char* string1, const char* string2);
  * @return true if the string is a integer, false otherwise.
  * @since v1.0.0
  */
-bool string_get_is_integer(const char* string);
+bool string_get_is_integer(const string string_value);
 
 /**
  * @brief Split a string into substrings using the specified separator and return them as an array and update the pointer `result_size` to the resulting size of the created array.
  *
  * @param string
  * @param separator
- * @return char**
  * @since v1.0.0
  */
-char** string_split(const char* string, char separator, size_t* result_size);
+string* string_split(const string string_value, char separator, size_t* result_size);
 
 /**
  * @brief Adds all the elements of an array into a string, separated by the specified separator string.
  *
  * @param array
  * @param separator
- * @return char*
  * @since v1.0.0
  */
-char* string_join(char** array, const char separator, size_t array_length);
+string string_join(string* array, const char separator, size_t array_length);
 
 /**
  * @brief Concatenate two strings.
  *
  * @param string1
  * @param string2
- * @return char*
  * @since v1.0.0
  */
-char* string_concatenate(char* string1, char* string2);
+string string_concatenate(string string1, string string2);
 
 /**
  * @brief Check if a string contains only unique characters.
@@ -167,7 +157,7 @@ char* string_concatenate(char* string1, char* string2);
  * @return true if string contains only unique characters, false otherwise.
  * @since v1.0.0
  */
-bool string_get_has_unique_characters(const char* string);
+bool string_get_has_unique_characters(const string string);
 
 /**
  * @brief Returns the part of the string between the start and end indexes (both included).
@@ -175,10 +165,9 @@ bool string_get_has_unique_characters(const char* string);
  * @param string
  * @param index_start
  * @param index_end
- * @return char*
  * @since v1.0.0
  */
-char* string_substring(const char* string, size_t index_start, size_t index_end);
+string string_substring(const string string_value, size_t index_start, size_t index_end);
 
 /**
  * @brief Check if a string contains a substring.
@@ -188,26 +177,25 @@ char* string_substring(const char* string, size_t index_start, size_t index_end)
  * @return true if the string contains the substring, false otherwise.
  * @since v1.0.0
  */
-bool string_get_is_substring(const char* string, const char* substring);
+bool string_get_is_substring(const string string_value, const string substring);
 
 /**
  * @brief Format a number to a string with specified separator.
  *
  * @param integer
- * @return char* example: string_get_formatted_number(1000, " ") => "1 000"
+ * @example string_get_formatted_number(1000, " ") // "1 000"
  * @since v1.0.0
  */
-char* string_get_formatted_number(const long long number, char* separator);
+string string_get_formatted_number(const long long number, string separator);
 
 /**
  * @brief Returns a pointer to the last occurrence of character in the string.
  *
  * @param string
  * @param character
- * @return char*
  * @since v1.0.0
  */
-char* string_get_last_occurence_of_character(const char* string, char character);
+string string_get_last_occurence_of_character(const string string_value, char character);
 
 /**
  * @brief Check if a string starts with a substring.
@@ -217,7 +205,7 @@ char* string_get_last_occurence_of_character(const char* string, char character)
  * @return true if the string starts with the substring, false otherwise.
  * @since v1.0.0
  */
-bool string_starts_with(const char* string, const char* prefix);
+bool string_starts_with(const string string_value, const string prefix);
 
 /**
  * @brief Check if a string ends with a substring.
@@ -227,6 +215,6 @@ bool string_starts_with(const char* string, const char* prefix);
  * @return true if the string ends with the substring, false otherwise.
  * @since v1.0.0
  */
-bool string_ends_with(const char* string, const char* prefix);
+bool string_ends_with(const string string_value, const string prefix);
 
 #endif
diff --git a/lib/terminal.c b/lib/terminal.c
index 53ce1bb..c7fbb7e 100644
--- a/lib/terminal.c
+++ b/lib/terminal.c
@@ -1,22 +1,22 @@
 #include "terminal.h"
 
-char* terminal_input() {
+string terminal_input() {
   char character;
   size_t length = 1;
-  char* string = malloc(length * sizeof(char));
-  if (string == NULL) {
+  string string_value = malloc(length * sizeof(char));
+  if (string_value == NULL) {
     exit(EXIT_FAILURE);
   }
-  *string = '\0';
+  *string_value = '\0';
   while ((character = getchar()) != '\n' && character != EOF) {
     length++;
-    string = realloc(string, length * sizeof(char));
-    if (string == NULL) {
+    string_value = realloc(string_value, length * sizeof(char));
+    if (string_value == NULL) {
       exit(EXIT_FAILURE);
     }
-    character_append(string, character);
+    character_append(string_value, character);
   }
-  return string;
+  return string_value;
 }
 
 void terminal_print_array(void* array, size_t array_size, size_t element_size, void (*print_element)(void*)) {
diff --git a/lib/terminal.h b/lib/terminal.h
index a570f9c..b6bc2d6 100644
--- a/lib/terminal.h
+++ b/lib/terminal.h
@@ -14,11 +14,9 @@
 
 /**
  * @brief Read a line from stdin.
- *
- * @return char*
  * @since v1.0.0
  */
-char* terminal_input();
+string terminal_input();
 
 /**
  * @brief Print an array.
diff --git a/main.c b/main.c
index 7b0f915..e20f966 100644
--- a/main.c
+++ b/main.c
@@ -4,8 +4,8 @@
 #include "libcproject.h"
 
 int main() {
-  char* string = "Hello, world!";
-  printf("%s\n", string);
-  printf("string_length = %ld\n", string_get_length(string));
+  string string_value = "Hello, world!";
+  printf("%s\n", string_value);
+  printf("string_length = %ld\n", string_get_length(string_value));
   return EXIT_SUCCESS;
 }
diff --git a/set_version.c b/set_version.c
index 5ab8d78..c4c2a47 100644
--- a/set_version.c
+++ b/set_version.c
@@ -3,12 +3,12 @@
 
 #include "libcproject.h"
 
-int main(int argc, char* argv[]) {
+int main(int argc, string* argv) {
   if (argc != 2) {
     fprintf(stderr, "Usage: %s <version>\n", argv[0]);
     return EXIT_FAILURE;
   }
-  char* content = "#ifndef __LIBCPROJECT_VERSION__\n";
+  string content = "#ifndef __LIBCPROJECT_VERSION__\n";
   content = string_concatenate(content, "#define __LIBCPROJECT_VERSION__ \"");
   content = string_concatenate(content, argv[1]);
   content = string_concatenate(content, "\"\n\n");