Lol, harizen is right. The question is very broad and one that could essentially take a whole essay to explain if one got down to minute details. To help OP embark on his/her 'do your own research' journey, we will leave a link to our blog below on the differences between bitcoin and ethereum. It's at the very least, a good place to start.
http://bit.ly/BTCvsETHvsLTCCheers