is a block of instructions grouped together under a method name. Since this block does not return any results of it's efforts it is called a procedure. A useful rule of thumb on when to implement a set of instructions as a method or function is, could these group of commands be used again in the future of this project.
Procedure DoSomething(Para:String); begin Writeln(%u2019Got parameter : %u2019,Para); Writeln(%u2019Parameter in upper case : %u2019,UpperCase(Para)); end; begin DoSomething('Hello World!'); end.Source: Reserved Words