"Cold wallet" is a term used to refer to devices that store cryptocurrency private keys offline. Private keys are transferred from a device with an internet connection to a device that does not. This data security technique has been used by businesses, governments, and individuals for several decades to keep data inaccessible or save it for later use. In most cases, it is called cold storage, but cryptocurrency fans and users prefer to call a device that stores keys offline a cold wallet. Cold storage methods are useful for individual investors and users, but some of the best cryptocurrency exchanges and companies involved in the crypto space also make use of this type of storage.