It is simply printing your private and public keys on a piece of paper and keeping it in a secure storage where only you can access. (coinstaker.com)
You will have Private Key as well as Public key printed on the paper and you need to store a copy of this data at different places. (coinfunda.com)
Paper wallets contain both private keys and public keys printed on paper, and you can store this information in a safe place so no external hacker will be able to get your coins. (captainaltcoin.com)