I'm looking at my enchanting options and notice there are resist magic, fire, frost and shock enchantments. Is magic a separate school, or does magic encompass fire+frost+shock...

Bonus question: I also would appreciate any feedback as to whether magic resists are good idea for a 2-hand warrior with max heavy armor perks. I am playing a nord so I think I already get 50% frost resist.

Any feedback appreciated. Thanks.