Hey Darkenwrath,
They are essentially basic statistics on your opponents that can help you figure out how they play.
VPIP = % of hands they play
PFR = % of hands they raise
3B = % of hands they 3bet
CB = % of times the continuation bet
FCB = % of times they fold to a continuation bet
Lessons 4 and 5 of the beginner's course go completely in-depth in the basic use of stats and a HUD. Here's a link to lesson 4:
Lesson 4
You may find that some articles mention the PokerStrategy.com Elephant. This is basically a program like PokerTracker, except made by us. But that has been discontinued, and you can pretty much disregard every mention of it.
For now, if you don't really know what they mean yet or how to use them, it is probably best not to play with stats/a HUD yet, because you will probably only confuse yourself.
Hopefully that helps
Kind regards,
Tino