UPDATE: Stop ignoring--and start using--this security setting
By Wilson Rothman
Two-factor authentication comes in several forms
"Two-factor authentication." It's an ugly term for something that needs to be in your daily life.
But you also need to know its limitations.
First, though, let's start with something more basic: What is two-factor authentication? It's where you log into a website or app and, once you type in your password, you're prompted to do something else, like enter a six-digit code or tap a pop-up on your phone.
With two-factor, hackers need both your password and access to your phone or other "second factor" to break in. If you regularly log into Facebook,(FB) Gmail, banking and other accounts with just a password, you have a security hole.
Two-factor is generally easy to turn on. Every online service worth its salt has the option in its settings, though you may have to dig. (Doing a Google(GOOGL) search for "two-factor authentication" and then the website or app's name generally directs you to the setting, or to a how-to page about it.) And once you're logged in, it generally won't keep bugging you for that second factor, unless you log out manually or the service senses unusual account behavior.
Two-factor authentication for some top sites: