| Functions that a programmer writes will generally require a prototype. Just like an blueprint, the prototype tells the compiler what the function will return, what the function will be called, as well as what arguments the function can be passed. |
| Declaration means declaring something to the compiler. This tells the compiler that a function which looks like this is coming later on in the program. It is a statement which specifies the function name, argument types and return data type. |
| Function declaration is done before the main function itself. |
| Syntax |
| Return data type Function name (parameter); |
| Note that Function declaration should have a statement terminator. |