Two-Step Verification

Two-step verification is a process wherein it is verified by involving two authenticated methods one after the other that it is verified that there is a person requesting access or who he is or what has been declared.

The difference between two-step verification and two-factor authentication:
Two-step verification is sometimes confused with two-factor authentication (2FA), which includes two commonly sequential methods used for verification. However, unlike 2FA processes, two-step verification methods can be related to the same category of authentication factors, and the methods used for 2FA are not necessarily sequential.

Apart from this, verification and authentication are not entirely synonymous. Verification can be part of the real-world process - for example, granting driver's license as a proof of identity. Authentication is considered to be an optimization of automated and verification systems designed to protect online systems.

Even so, many 2-step verification products and services are also examples of two-factor authentication. For example, Google's 2-Step Verification service includes a generic password (the user knows something) and the code sent to the user's device (with some users). mostly other current web-based user authentication systems described as two-step verification also qualify as two-factor authentication.