Definition
A crypto wallet is software or a device that stores the private keys needed to control cryptocurrency and sign transactions; the coins themselves stay recorded on the blockchain.
How it works
Every wallet address comes from a key pair. The public part, shown as the address, can be shared to receive funds. The private key proves ownership and signs transactions, so anyone who has it can move the funds. Most wallets create their keys from a recovery phrase, also called a seed phrase: usually 12 or 24 words that can rebuild all of the wallet's keys on another device.
Wallets are grouped in two ways. In a custodial wallet, such as an account on a centralized exchange, a company holds the keys for you; in a non-custodial wallet, only you hold them. A hot wallet is connected to the internet, such as a phone or browser app, which is convenient for frequent use. A cold wallet, such as a hardware device or a key kept offline, keeps the private key away from the internet and is harder to attack remotely.
Blockchain transfers are usually final. Coins sent to a wrong address, or on a network the receiving wallet does not support, generally cannot be recovered by anyone. No legitimate service needs your recovery phrase, so a request for it is a sign of a scam.
Example (hypothetical numbers)
Suppose a user holds $10,000 of Coin A: $1,000 in a hot wallet on a phone and $9,000 in a cold wallet kept offline.
If the phone is hacked, the amount directly exposed is $1,000, or $1,000 ÷ $10,000 = 10% of the total.
If the phone is only lost, the user restores the hot wallet on a new device with the recovery phrase and sees the same amount of Coin A, because the balance is recorded on the blockchain, not on the phone.
The example shows that a wallet protects keys, and whoever holds the recovery phrase controls every address it created.
Common mistakes
- Believing the coins are stored inside the phone or hardware device.
- Saving the recovery phrase as a screenshot or in online notes.
- Sending a token on a different network from the one the receiving address uses.
- Assuming an exchange account gives the same control as holding your own keys.
Related calculators
This glossary is for education only and is not investment advice. Examples use hypothetical numbers.