Two-Factor Authentication (2FA) is a security process in which users provide two different authentication factors to verify their identity. This method creates a layered defense, making it more difficult for unauthorized users to gain access to a target, such as a computer, network, or database.

The two factors typically involved in 2FA are:

1. Something you know (e.g., a password or PIN)
2. Something you have (e.g., a smartphone or security token)