Token

A token (also referred to as a "security token," "hardware token," "hard token," "authentication token," "cryptographic token," or "key fob") may be a physical device or software that an authorized user of computer services is given to assist in authentication.

Tokens are used to prove one's identity electronically (as in the case of a customer trying to access their bank account). The token is used in addition to or in place of a password to prove that the customer is who they claim to be. The token acts like an electronic key to access something.