Network token is the shortest common name for a card network token, and that entry describes what the credential is, how it is provisioned and how it differs from a gateway token. This page explains how the shorter term is used.
A network token is a 16-digit or similar number that stands in for the real primary account number during a payment. It is issued through the card network's own token service and is restricted to a particular domain, such as one merchant's card-on-file store or one phone wallet. Each transaction made with it also carries a cryptogram, a one-time code that proves the token is being used by the party it was issued to. If a card is lost and reissued, the network can keep the token alive and link it to the new card.
People say "network token" when they want to stress who issued it: the network, rather than a payment gateway or processor. Payment teams compare "network tokens" with "PAN-based" transactions when measuring approval rates and fraud. The overall system is explained under network tokenization, the parties that request tokens under token requestor, and the identifier that links all tokens for one card under payment account reference. Network tokens are widely used for card-on-file transactions.