The digital coin vault is a program that stores records of cryptomonets on the hard disk of a computer (or other digital device), or a program designed to communicate with an Internet service within which coins are stored. When performing each transaction, the program communicates with a blockchain "ledger", where records of the movement of each transaction are stored, the cryptosystem checks the legitimacy of the payment and, in fact, transfers coins. Regardless of the type of wallet, in order to gain access to their funds, the user must enter a private key, the storage of which will be given special attention in this article.

Digital coins of various crypto networks can only be circulated in the infrastructure of the network where they are issued, so there is simply no way to place, for example, Ethereum coins in a bitcoin wallet. Promising, interesting cryptocurrencies became more and more over time, and users needed a repository where they could keep coins of different cryptosystems. And soon the market offered a solution – online services appeared where you can open online wallets of different crypto networks within the same account (while the coins rotate each in its own network).