Two-factor authentication provides stronger security than single-factor authentication like usernames and passwords alone. It requires two factors: something you know (like a password) and something you have (like a token, smart card, or biometric). This makes hacking accounts more difficult as possessing just a password is not enough. While more secure, two-factor authentication has additional costs and may be inconvenient for users. However, as technology advances, the use of two-factor authentication is growing in industries like banking and online brokerages to better protect customers.