Multifactor Authentication

Multi-factor authentication (MFA) is a simple way of protecting employee profiles by requiring an employee to provide more than just their username and password when attempting to log in. In Office 365, multi-factor authentication adds a second layer of protection that requires an employee to provide proof of their identity before they are granted access to a profile. For example, if someone managed to crack or steal your password but doesn’t have the device you associated with your profile, they won’t be allowed to log in. So that second factor—the mobile or office phone—will protect your account from unauthorized logins.

Refer to attachment "MFA Setup Instructions v2"