I know i a newb for asking but wat does deploy mean when you are selecting your mission

Deploy, just like in today's military, simply means whatever ships you send on a deploy mission (only possible within your own Empire), will stay at the coordinates you typed in.

okay makes sense and do they defend the coordinates as well

Yes they do.

thx

I really think you should stop wasting time asking questions that are answered in the guides that are provided. Stop and read a littl bit and you will learn a great amount about the basics of the game and some advanced tips as well.