Continuation bet is an term specific for poker, specifically in the community cards games (Texas Hold’em, Omaha). This is a wager made on the flop by the raiser, with the size generally between 1/2 pot and the whole pot.
In Texas hold’em, in general, a player improves his hand substantially once in three at most. The continuation bet has the effect of forcing the opponent to fold often enough. If the opponent folds once in three, a bet of 2/3 of the pot size has zero expectance, even if the bettor abandons the blow when the bet is paid. It is therefore a virtually automatic blow. However, running or not continuation bet depends on the position, of the composition of the board, tendencies of the opponent, and finally the hand of the reraiser. A continuation bet out of position is dangerous as a savvy opponent speaking last can simply pay this bet hoping to steal the shot later, since he knows that the initial bettor has a good chance to have a low play.
So we made a continuation bet for two main reasons:
For the value of our hand: eg AA with a tricolored flop A72.
To take the pot right away, eg with 89 on a flop KT2. Off position however this can be quite risky.
Having bet regardless of the strength of his hand makes a player less readable.
The following factors make up the continuation bet less effective, and the presence of one or more of these factors make it negative:
Many players on the flop (at least three)
The lack of position (speaking first)
A dangerous community cards (ex. 9JT with three hearts) is a very important criterion in Omaha
Opponents who pay very broadly
The continuation bet can also be performed on the turn if there was no flop bet (usually against opponents with too broad trends in flop), or more rarely on the river.
We can respond in several ways to the continuation bet: the float is to pay the continuation bet (preferably in position) to steal the spot later (usually on the turn). One possible defense against the float is double barrel, which is a bet on the turn performed in addition to the continuation bet.