What are the rules for comparing strings in the C language?

In the C language, string comparison is typically done using the strcmp function. The rule for string comparison is to compare each character in the strings in dictionary order until a different character is found or one of the strings reaches the end character ‘\0’. The result of the comparison is an integer value: 0 if the strings are the same, a negative number if the first string is less than the second, and a positive number if the first string is greater than the second. The strcmp function is case-sensitive, but if case-insensitive comparison is needed, the strcasecmp function can be used.