Do you have to play gears of war to understand gears of war 2

You don't have to play the first installment to enjoy the second Gears of War, but i recommend playing the first if you want to understand the storyline. If you're just about blowing stuff up and "poppin' heads," just get the second one.

P.S.
I personally prefer the tight-knit GoW1 community to the GoW2 community, i also enjoy the multiplayer in general for #1 more than 2