The continuation bet is a very commonly talked about strategy in poker. To briefly describe what it is – It is a bet made on the flop when you where the preflop raiser, regardless of whether you connected with the flop or not.
There are many reasons that players would deploy this strategy as part of their game. The main reason you would use a continuation bet is that people will miss the flop about two thirds of the time so you will win the pot with a bet a good % of the time so will likely show a profit long term just by betting.
Another reason that people continuation bet is because if you where the raiser preflop you have the “psychological betting lead” which means that it is more natural for you to be the one to bet the flop than any other people and as a result people will respect that bet more.
By continuation betting even when you have missed the flop you make your opponents guess all the time as to whether you have hit the flop or not and so you become harder to play against and when you actually do make a hand you will likely get more action from other players as you would make the same bet even if you totally missed the flop.
When you have drawing hand like an open ended straight draw or a flush draw a continuation bet will sometimes will the pot right there and other times you will start to build a bigger pot which will make it easier to win more money if you make your hand as the pot will be bigger and therefore your valuebet can be bigger.
Continuation bets can also continue down the streets. If you where the aggressor on the flop you can make a continuation bet on the turn which looks very strong and can get some players to fold strong hands to you even if you are only doing it with a marginal hand or a drawing hand. In general this sort of aggressive style of using a lot of continuation bets even when you have missed makes it difficult to play against you and will ultimately win you more money in the long term.
Just be careful as not to keep firing into a player who very clearly has a strong hand. When you play like this people will realise and start to check/call with all their strong hands knowing you will bet.