Why don't siblings look exactly alike?

Accualy some do, but that's a little rare, so I'm guessing because each child gets some of there mom and dad's to genetics, one child might get some of there mom's but more of there dad's and the other might get some of there dad's and more or there mom's..? not sure if that makes any sense-

the answer to this predicament is false, by friend, i had this on a quiz, and i got it wrong, so i learned it, cos i was gonna have it on a test, and i got it right