What macros in word & excel used for?

The macro is used to record the number of repetitive steps and helps to perform tasks quickly 

Plus 

Possibility of complex software to facilitate business

Macros are a really great relaef for the burdeous work in all branches of Ms Office works.

Sir Faridullah Shah Farid

here is method given by MS for its use and recording.

http://office.microsoft.com/en-001/excel-help/quick-start-create-a-macro-HA.aspx

Hope it helps.

Macros Is So Much Fun And Easy To Use , 

You Do Something That You Ussualy Do , Maybe Like Color The Header , Hide Some Coloms , Delete The First Row , Change Head Of Colomn So Instide Of Doing All That Every Time You Record Your Moves For Once And You Just Click One Click Excel Will Do The Rest Again And Again , That Easy