The function strcpy is a standard library function in the C programming language used to copy strings. It takes two arguments: the destination string and the source string. The function copies the characters from the source to the destination until it encounters a null terminator, which marks the end of the string. It's important to ensure that the destination string has enough allocated memory to hold the copied content, including the null terminator. Failing to do so can lead to buffer overflows, which may cause program crashes or security vulnerabilities. Proper usage of strcpy is crucial for safe string manipulation in C.