You need to watch the odds and then decide how many outs you have to continue the game. Let's say you need to invest their 1000 bank 5000. Odds of 1: 5. After the flop you do not see 47 card. And if you're in this situation, there is at least 6 outov, it is necessary to continue the game.
Generally this great poker theme. And I advise you to read professional literature. In 2-3 sentences can not explain everything thoroughly. But for a successful game you just need to be able to count outs and pot odds
. And it is correct to apply their knowledge.