Two-factor authentication: What you need to know (FAQ) | Security & Privacy - CNET News

Summary version: if your service provider supports 2FA, use it...

"Twitter announced on Wednesday that they've started supporting two-factor authentication, joining a growing list of major Web services that offer the more secure login method.
Two-factor authentication, or 2FA as it's commonly abbreviated, adds an extra step to your basic login procedure. Without 2FA, you enter in your username and password, and then you're done. The password is your single factor of authentication. The second factor makes your account more secure, in theory."

Two-factor authentication: What you need to know (FAQ) | Security & Privacy - CNET News