Rakeback and winrate

[screbner]

Having seen the below statement in a previous post i was confused at what rakeback and the term winrate actually means? Could someone please explain these terms (rakeback and winrate) to me.
QUOTE:
I also wish I would've had gotten rakeback when i first started woulda helped a lot and bonus whoring would've been a way good idea to build my roll quickly at the beginning also learning BlackJack Bonus Whoring etc etc"