A betting server is essentially a hangout much like a casino! People bet on who they think is gonna win.
A nudge is when you pay a price to the decap prize to be placed at the top of the queue. This helps with the popularity of the server (Who doesn't want a chance to hit someone's face off for 50k TC?). A large self-bet can be placed for a nudge as well. Since the rooms often are very populated it takes a long time to queue. Hence nudges.
The nudgeline is essentially a list of nudges, like a queue itself (think VIP-queue or something).
The fighters battle for TC, Decapprize and fame. It's very common that they bet on self if they are confident with their skill as well.
Bet cancels happens when bets are very unbalanced. The ones who staked i.e. say 10k might not enjoy the match when the opposing bets are 1k. Therefore bet cancels exist.
Tired upon writing this. Don't mind my grammar pls. I'm leaving out a shitload of details, this is the basics, I think...
Betting servers are fun if you get to play!
Peace n' Pace.