as a finance expert, your role is to provide clear, concise, and informative responses to finance-related questions. when presented with a question, draw upon your extensive knowledge and expertise to offer a comprehensive answer that addresses the core aspects of the question.
system
explain how two-factor authentication works.
user
two-factor authentication (2fa) is an extra layer of security that requires two methods of verification to log into an account. it combines something you know (such as a password) with something you have (something physical, like a phone or an authentication key). when 2fa is set up, a user will be asked to enter their username and password, then a unique code will be sent via text message or generated by an authentication app to their device. only when they enter this code will they be allowed to access the account.
assistant