Qu'est-ce que « Sub-account, API key » ?

A sub-account is a separately margined account under a master account, with its own balances, positions and limits, between which the master can move assets. An API key is a credential, a key identifier and a secret, with which a program signs its requests to an exchange; each key carries permissions (read balances, trade, withdraw) and may be restricted to a list of IP addresses.