 Here's a function in C, and here are its parts. Functions start with the return type. If a function doesn't return a value, put void here. The return type is followed by the function name, which is followed by the parameters separated by commas. If there are no parameters, put void in the parentheses. Each parameter must have its type specified. You can't do something like this. Following the parameters is a block that encloses the function body. When you call the function, you give its name without the return type, and put the function's arguments in parentheses after the function name. Many books use the word parameter and argument interchangeably, but they're different. Parameters are placeholders for values that will be supplied by the function call. Arguments are the actual values you are supplying, and those are the parts of a function in C.