What defines a string in C?

A string in C is specifically defined as an array of characters that is terminated by a null character. This null character, represented as '\0', marks the end of the string and signals to functions that operate on strings where the string concludes. This means that even though a string may contain a sequence of characters, it is the null terminator that allows functions to know how much of the array is actually used for the string.

In C programming, strings are not inherently dynamic in size; rather, they are typically fixed-size unless managed through dynamic memory allocation. Thus, while it is possible to create arrays of characters of varying sizes at runtime, the concept of a string relies on this null termination for proper handling in functions like printf, strcpy, or strlen. This ensures that the program correctly identifies when it has reached the end of the string data in memory.