Bitcoin wallets are used to manage each users public-private key pair. These wallets can be online, desktop, mobile, paper, or hardware. Also, these wallets are divided into two different groups: hot wallets and cold wallets. The difference refers to how they manage the private key of the user’s public-private key pair. If the private key is generated and stored offline, then it is in a cold wallet. If the private key is generated and stored online, then it is in a hot wallet.