What's the difference between a method and a selector?

Question

What the difference between a method, a selector and a message in Objective-C?

Answer 1

This site has a good overview of all the terminology in question: http://www.otierney.net/objective-c.html

Check out the link, but I'll give a quick summary:

A method is essentially like a method of function that you are used to in your favourite programming language.

A message (from the article) "A message can be dynamically forwarded to another object. Calling a message on an object in Objective-C doesn't mean that the object implements that message, just that it knows how to respond to it somehow via directly implementing it or forwarding the message to an object that does know how to."

Selectors can mean two things. It can refer to the name of a method, or "refers to the unique identifier that replaces the name when the source code is compiled. Compiled selectors are of type SEL." (from: http://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/ObjectiveC/Chapters/ocSelectors.html)