inet_ntop is a function in C programming language that converts an IPv4 or IPv6 binary address into a string representation of the address in standard dot notation (for IPv4) or colon-hexadecimal notation (for IPv6). It takes as input the pointer to the binary address and the size of the address structure, and returns a pointer to a string representing the IP address. The function supports both IPv4 and IPv6 addresses, making it useful for network programming tasks where IP addresses need to be displayed or manipulated.