According to the 10 Tips for Secure Online Transactions - SmartAsset article, multi-factor authentication is a security measure that requires users to provide more than one piece of evidence to verify their identity when logging in to an online account. For example, users may need to enter a password and a code sent to their phone or email, or use a biometric feature such as a fingerprint or a face scan. Multi-factor authentication can help secure online financial transactions from improper users, as it makes it harder for hackers to access the account even if they have the password. Multi-factor authentication can also alertusers to any suspicious login attempts and prevent unauthorized transactions. References = 10 Tips for Secure Online Transactions - SmartAsset