what are master spells and how do you get them? is it a certain level you have to be in a class like illusion, conjuration, destruction ect??????

Sorry OP i don't know either

Master Spells can't be bought in Winterhold College or any shops, they must be through a quest. First you've got to get 90 to 100 skill in a school, then you visit the npc of that school in Winterhold College (Faralda for destruction, etc.) who will give you the quest and voila, master spell is yours. Probably goes for the other schools, but I've only don destruction so far.