Authentication is the practice of verifying the identity of a user. Authentication is performed to verify that a user is who they claim to be. When user gets verified, the user is granted access. This way, authentication guarantees the safety of a network and the data of an entire organisation.
It is recommended to use at least two different authentication methods while logging to systems. Activating multi-authentication where possible will improve your credential security dramatically. Authenticators are great way to serve this purpose as they are reliable and easy to use.