Defined in BIP32 and standardised by BIP44, BIP84 (native SegWit, m/84'/0'/0') and BIP86 (Taproot, m/86'/0'/0'). If a restored wallet shows zero, the wrong path or script type is a common cause.
Glossary · deep dive
Derivation path
The 'route' (for example m/84'/0'/0') a wallet uses to derive keys from a seed. Needed to find coins when restoring.