My rear hatch window was smashed the other day and I was wondering if anyone knows what the actual name of the part is called or where I can find the part without going to a dealer or how much one is going to cost. Thanks.

Good luck. Call an auto glass company and let them do it. Don't mess with that shit.

"Rear hatch glass"
What year is it.

http://www.car-part.com/index.htm
try here

if it's 94 or older and an s10 model the glass will work from an s10 blazer, a gmc jimmy or an oldsmobile bravada, and from 1984 and up all the rear hatch glass is the same, you should have no problem going to a junkyard and finding a replacement for cheap, and it's really easy to change just take care when screwing the hinges into the glass, don't overtighten, afterall it is glass your screwing into.