A program which takes an id as input and tells us that is it valid or invalid?

A program that validates an ID typically checks the format, length, and specific criteria associated with that ID type. For example, it may verify that the ID contains only certain characters or numbers and matches a predefined pattern. If the ID meets all the requirements, the program will return "valid"; otherwise, it will return "invalid." This process helps ensure that only correctly formatted and legitimate IDs are accepted.