This is the method of keeping your address and private key printed on paper. The main purpose of this is to store your information long-term. It is secure because it is cut off from the Internet entirely, and thus is resistant to hacking or computer equipment failure.
Once you print it, keep it in a safe place. Once you have printed it, it is safest to delete browser, PC, and printer caches.
If you lose your paper wallet or it is destroyed by fire, you run the risk of losing your Bitcoin forever. Be careful where you choose to keep it. When sending money, a user must import this information to a wallet, so it is not very convenient.