Your bankroll, and how long it lasts, determines how long you can go on playing Blackjack. It determines how much money you can win, at least from the beginning. For this reason, you want to do a good job of managing it so that you can have the most success possible — both winning the most that you can and playing for as long as possible without going broke. There are a handful of things that you can do to make sure your bankroll is used effectively.
First of all, start betting low if you do not have a lot of money. Do not try to just come in and put everything down on the first hand. If you win, this will give you an incredible start to a very fun night. However, your night will be over if you lose. This is just too big of a risk to take all at once, especially since there are such better choices that you can make. Gambling is all about taking risks, but the art of gambling successfully — many people are good enough at it that they can play cards for a living — is to take only the best risks, the ones with the best odds of success. What you will want to do is to bet little amounts at the start and work your way up to the bigger bets. This will take some patience, but you can play for a lot longer if you wait for your bankroll to grow to the point that you can use it how you want to.
It is also a good idea to just bet the same amount every time that you play and on each hand. Many players are tempted to throw down big bets every now and then to make up for lost ground. This is not a good idea and just leads to their digging that hole even deeper. Instead, put down the exact same bet each time. The obvious way that you should break this rule is if you have started small and now have enough to increase your standard bet — still, you should increase it to a constant number for the night. This way you will not lose large bets and only win back smaller amounts.