A Google Account lets you organize and access your personal information from any computer or mobile device:

• Never lose your contacts again. When you sign in to your phone with a Google account, all the contacts you associate with that account in the People app are automatically backed up. As a result, they're always accessible through your Gmail account from any computer.
• Synchronize and back up everything. Whether you draft an email, add a contact's phone number, add an event to your calendar, or take a photo, your work gets backed up continuously by Google and synchronized with any computer where you use the same Google Account.
• Access from anywhere. Check your latest calendar, email, text messages, or social stream, wherever you are, no matter what computer or mobile device you're using.
• Keep your stuff secure and available. Google works round the clock to protect your personal data from unauthorized access and to ensure that you get it when you need it, wherever you need it.
• Use other Google services. Your Google Account also lets you take full advantage of any other Google apps and services that you may want to use, such as Gmail, Google Maps, Navigation, Android Market, YouTube, Google Talk, Messaging, and many more.