The term cold storage is a general term for different ways of securing your bitcoins offline (disconnected from the internet). This would be the opposite of a hot wallet or hosted wallet, which is connected to the web for day-to-day transactions. The purpose of using cold storage is to minimize the chances of your bitcoins being stolen from a malicious hacker and is commonly used for larger sums of bitcoins.
A collective term for various security measures to reduce the risk of remote or unauthorized access to private keys. It could be a personal computer disconnected from the internet, a dedicated hardware wallet, a USB stick with a wallet file, or a paper wallet.
Malone, J.A (2015). Glossary of Bitcoin Terms and Definitions. United States: Lulu Press, Inc