What is the difference between pitching appearances & relief appearances?

In the Yahoo stat options for a commish in a custom league there is an option for pitching & relief appearances.  So my question really is, would a relief pitcher get both stats since he's technically making both appearances or does a pitching appearance go just to the starter & the relief pitcher just get the relief appearance?  Asking for a friend. Also I'll never type the word appearance so many times ever again.