Definition
In a hierarchical deterministic wallet, an "account" is a distinct branch of the key tree that holds a self-contained set of funds. Under the BIP44 path structure m/purpose'/coin_type'/account'/change/address_index, the account sits at the third level and is hardened. Accounts are numbered sequentially from 0, and each one carries its own external (receive) and internal (change) address chains.
Why separate accounts exist
Accounts let a single seed back several independent identities or money pools without ever mixing their coins, much like having multiple bank accounts under one login. You might run separate accounts for personal spending, business income, a donation address, or savings you want to keep visually and operationally distinct. Because the account level is hardened, exposing one account's keys does not endanger the others or the master seed.
Watch-only and account discovery
Each account exports its own extended public key (xpub), so you can hand a single account's xpub to an accountant or point-of-sale system while keeping the rest of your wallet entirely private. During recovery, wallets perform "account discovery": they scan account 0, and only proceed to account 1 if account 0 shows activity, stopping at the first empty account.
The account model is built directly on BIP32 HD wallets and depends on hardened derivation for its isolation guarantees, both foundations of practical self-custody.
In Simple Terms
In a hierarchical deterministic wallet, an “account” is a distinct branch of the key tree that holds a self-contained set of funds. Under the BIP44…