Unlike other methods of authentication multi-factor authentication uses two or more pieces of evidence to an authentication mechanism such as knowledge, possession, and inference. After the authentication one can get access to the website or the application. Relative to knowledge, a person might be required to answer a given question with a preset answer. Relative to possession and inference a code might be sent to the person's phone. As such, a multi-factor authentication is indeed a reliable form of authentication. Today, there are numerous solutions in the market which provide the user with multi-factor authentication. The following are the things to consider when choosing the top multi-factor authentication solutions.