Crypto Wallet is software that communicates with the Bitcoin blockchain network. A wallet can be on your phone, computer, website and even on paper. Each wallet has an address, and each address is linked to two types of keys: private and public. To hold Bitcoin, you need to hold its private key. Usually the keys will be represented by a string of letters and numbers, and in fact everything that 'holds' the private key is called a wallet. If we chose to keep the private key on a sheet of paper, that means we have a paper wallet. If we chose to keep the private key in a computer program, that means we have a computer wallet.