noob question from experienced player

I feel real dumb asking this question since I've been a reader/semi-poster on this site/poker player for a while, but can someone explain exactly what bb/hands means?

Example: 3bb/100 hands.

I'm pretty sure it means big bets as opposed to big blinds, but how do you determine that value of that big bet? Is it in comparison to the blinds of the table, or your stack size, or both?

Thanks in advance.

Correct me if I'm wrong but i think big bet is just double the big blind. The term comes from limit holdem.

Thats right.

bb/100 = PTBB/100 = Poker tracker Big Bets per Hundred hands.

The big bets are from Limit where a big bet is equal to 2 big blinds.

The reason we use PTBB/100 in no limit is because most of us track our results with pokertracker which was originally designed for limit holdem so poker tracker measures winrates with big bets.