Does two-factor authentication protect me from hackers?

What is two-factor authentication and why should I care about it? Does it really help protect me from hackers? Matt Cutts, Bay Area, California Learn how to get 2-step verification on your Google Account here: support.google.com Video overview: www.youtube.com Have a question? Ask it in our Webmaster Help Forum: groups.google.com Want your question to be answered on a video like this? Follow us on Twitter and look for an announcement when we take new questions: twitter.com More videos: www.youtube.com Webmaster Central Blog: googlewebmastercentral.blogspot.com Webmaster Central: www.google.com