Extended Public Key (xPub)

Part of the Bitcoin standard established by BIP 32, an extended public key (xPub) is a public key enriched such that it can be used to derive child public keys. 

xPubs, an element of HD wallets like the BitBox 02 and Trezor hardware wallets, are used to derive public keys. In turn, public keys are used to generate a wallet address that crypto assets can be sent to and from.

A benefit of an xPub is that the private key of a wallet remains offline.