A Google Account operates as a single Google login, made up of an email address and password of your choosing. It gives you access to various Google services, including AdWords, Google Groups, Google Alerts, Google Product Search, Personalised Search, your Personalised Homepage, Google Answers and much more. If you've used any of these services before, you already have a Google Account. If you have a Google Mail account, you can use your Google Mail username and password to sign in to your Google Account.
You now have the option to add YouTube as a service to your Google Account, linking the two. There are a few ways you can do this: