The world of insurance is so wide, that you will be asked if you would like to insure your blackjack hand. Of course this insurance is different than that stuff for your car and house, but it is also meant to protect you.
In blackjack, you are given two cards, and then dealer also receives two and then the fin begins. Because you can only see one of the dealer's cards, you have to decide what your next move will be. The best way to behave in any hand of blackjack is to consistently follow the basic strategy principles.
If the dealer is showing an Ace, you will have the option to buy insurance. To do this, you must place half the amount of your bet up for an insurance bet. There is a special spot on the blackjack table for the insurance bet, as it is a separate event from your original bet.
If the dealer reveals a blackjack, you are paid 2 to 1 on your insurance. If you are following along with the count here, then you realize you win the amount of your original bet back. In a long term blackjack strategy, the insurance is not a good mathematical decision.
If a dealer has the Ace for an up card, remember, there are still 9 cards that could give them a total other than a blackjack. If you do have a very large bet at the table, then it may be consideration for you to manage your bankroll. Hopefully, this is not a situation will find yourself in often.