A crypto wallet is an app or device that stores the keys to your digital assets and lets you send and receive them.
In plain words
The coins themselves “live” on the blockchain, and the wallet keeps the keys with which you sign transactions. Wallets can be custodial (an exchange or service controls the keys) or non-custodial (you control the keys, and the responsibility and the risk of loss are yours). By storage method they are split into hot (connected to the internet) and cold (offline). Providers of non-custodial wallets have no custody of your funds: they only supply the interface.
Sources
- ethereum.org: Crypto wallets — Wallets page. Checked 14.10.2026.
Example. An exchange shows you a deposit address: that is a custodial wallet, with the keys held by the exchange. A mobile wallet app where you keep the seed phrase yourself is non-custodial.