Storing crypto away from the internet. Meaning on a paper wallet, in a hardware wallet, or on an air-gapped machine. 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 cryptocurrency being stolen from a malicious hacker and is commonly used for larger sums of cryptocurrency.

The Ledger Wallet is a popular hardware wallet for cold storage of multiple cryptocurrencies.