What is a Google Account?
A Google Account functions as a master Google login, made up of a single email address and password.
Although a Google Account is similar to an AdSense login, your Google Account lets you easily jump to any of your Google services that also share this login (such as Google Groups, Google Mail and Google Product Search). This way, once you are signed in, you stay in - no more logging in and out between multiple services.
For more information, visit the Google Accounts Help Centre.