What is "method"

Definition:

In object orientation, one method is a subroutine which is executed by a object when receiving a message. Methods determine the behavior of objects of a class and are analogous to the functions or procedures of structured programming. Sending messages (called methods) can change the state of an object.

Example (Java):

public class Exemplo {
   public static void main(String[] args) {   //método main
      int raio = 3;
      System.out.println(area(raio));   //chamada ao método area
   }

   public static float area(int r) {   //método area
      return(3.1415f * (r * r));
   }
}