A wallet on a blockchain is analogous to an account on a ledger. Cryptocurrency can be sent to and from a wallet, or kept on it.
The access to this account is granted through a private key, which takes the form of a string of characters or a list of either 12 or 24 words.
Transactions made to or from a blockchain wallet are done using a public address (or public key). This key is a crunched down version of the private key, that doesn’t grant access to the wallet, but allows to check its transaction on the blockchain, and to send cryptocurrency to it.
Centralized crypto exchanges (CEX) manage wallets on behalf of their users. This means that they detain the private key on their behalf and have full access to the cryptocurrency in the wallet.
