blew head gasket and some lifter??

called my mechanic said i blew a head gasket and a lifter? what is a lifter? something inside the engine all i know is that my head gasket was leaking and it got like cooland and water inside the pistons (which explains the smoke) and then he said it messed up a lifter? he said that would cost 200 to fix and 950 for the head gasket… F*** that im having my friend come by with his F250HD and were towing my baby back home and going to work on it. can someone enlighten me on this lifter?

edit* found out what a lifter is. is it an easy fix/