The three types of authentication are something you KNOW, something you HAVE, and something you ARE. A multifactor authentication uses 2 or more of these factors. A credit card is something you HAVE while a PIN is something you know.
Multi-factor authentication (MFA) is a method of computer access control in which a user is granted access only after successfully presenting several separate pieces of evidence to an authentication mechanism – typically at least two of the following categories: knowledge (something they know), possession (something they have), and inherence (something they are).
Two-factor authentication (also known as 2FA) is a method of confirming a user's claimed identity by utilizing a combination of two different components. Two-factor …