Two-Factor Authentication verifies that you are who you say you are, when logging into a website, network, or cloud service. Having the correct login information is not enough. It can be stolen. Two-Factor Authentication requires the use of two of the three authentication factors identified in the Standards and Regulations for access to U.S. Federal Government systems:
True Two-Factor Authentication requires the use of solutions from two or more of the three categories of factors listed above. It is the most common form of Multi-Factor Authentication.