Multi-factor authentication is a process in which users are prompted during the sign-in process for an additional form of identification, such as a code on their cellphone or a fingerprint scan. If you only use a password to authenticate a user, it leaves an insecure vector for attack. If the password is weak or has been exposed elsewhere, an attacker could be using it to gain access. When you require a second form of authentication, security is increased because this additional factor isn't something that's easy for an attacker to obtain or duplicate. MFA works by requiring two or more of the following authentication methods, something you know, typically a password. Something you have, such as a trusted device that's not easily duplicated, like a phone or hardware key. Something you are - biometrics like a fingerprint or face scan. MFA can also further secure password reset.