The simplest description of a cold wallet is that it is not connected to the internet and therefore stands at a far lesser risk of being compromised. These wallets can also be referred to as offline wallets or hardware wallets. These wallets store a user’s private key on something that is not connected to the internet and can come with software that works in parallel so that the user can view their portfolio without putting their private key at risk.
Perhaps the most secure way to store cryptocurrency offline is via a paper wallet. A paper wallet is a wallet that you can generate off of certain websites. It then produces both public and private keys that you print out on a piece of paper. The ability to access cryptocurrency in these addresses is only possible if you have that piece of paper with the private key. Many people laminate these paper wallets and store them in safe deposit boxes at their bank or even in a safe in their home. These wallets are meant for high-security and long-term investments because you cannot quickly sell or trade bitcoin stored this way.
A more commonly used type of cold wallet is a hardware wallet. A hardware wallet is typically a USB drive device that stores a user’s private keys securely offline. Such wallets have serious advantages over hot wallets because they are unaffected by viruses that could be on one’s computer. With hardware wallets, private keys never come into contact with your network-connected computer or potentially vulnerable software. These devices are also typically open source, allowing the community to determine their safety through code audits rather than a company declaring that they are safe to use.
Cold wallets are the most secure way to store your Bitcoin or other cryptocurrencies. But they require more technical knowledge for set up.
A good way to set up your wallets is to have three things: an exchange account to buy and sell, a hot wallet to hold small to medium amounts of crypto you wish to trade or sell, and a cold hardware wallet to store larger holdings for long-term durations.