You can use Gmail to read and write email from any mobile device or browser. All your email is always up to date and available no matter where you check it from.
But Gmail is not just about email. Your Gmail name and password signs you into to all Google apps and services, including Calendar; People, for keeping track of your contacts; Picasa, for storing and organizing your pictures; Google Reader, for keeping up with your online reading; Google Documents, for working with documents, spreadsheets, or drawings; and many more.
on a Home or All Apps screen.The first time you launch Gmail, you're asked to sign in or create an account, if you didn't already do so when you first set up your device. Then Gmail opens to the Inbox. From here, you can:
While you're reading a message:
No matter where you are within Gmail, you can always get back to the Inbox by touching in the top left corner of the screen.