Macros
A macro is defined as "A macro in computer science is an abstraction, that defines how a certain input pattern is replaced by an output pattern according to a defined set of rules."
As WoWWiki says: "In the World of Warcraft, a macro is a method of combining several actions to execute in a single button press or keystroke."
These can be a great asset to save you time and effort when in the game.
An example of a simple macro you could use in UNITY when others whisper you asking to join is:
/w Thanks for your interest in the UNITY Guild. The best place to apply is via the website at www.wow-unity.com. Look at the recruitment section on the front page. Good luck!