Which user account is right for me?
A user account is a collection of info and settings that you use to interact with your PC and personalize Windows to work the way you want. For example, your user account determines which files and folders you can get to, the changes you can make to the PC, and your personal preferences, such as your desktop background or screen saver. If you share your PC with several people and don't want everyone to see all your files and settings, you can create separate user accounts for each person, and give each one a different user name and password.
There are three types of accounts. Each type gives you a different level of control over the PC:
Standard accounts are for everyday use. You probably created this type of account when you first started using your PC.
Administrator accounts provide the most control over a PC. To help protect your PC (and keep other people from making changes you don't want), administrator accounts should be used sparingly. You'll need to use an administrator account if you're setting up accounts for other people on your PC.
Guest accounts are useful when people need to use a PC temporarily.
You can turn on your PC's guest account in Control Panel.
Why sign in with an email address?
You can use an email address and password to sign in to Windows, and this becomes your Microsoft account. This can be either a standard user account or an administrator account—signing in with an email address is the important part. When you sign in with a Microsoft account, your PC is connected to the cloud and:
Your friends’ contact info and statuses automatically stay up to date from your Outlook.com, Facebook, Twitter, LinkedIn, and other accounts.
You can get to and share your photos, documents, and other files from places like Microsoft SkyDrive, Facebook, Flickr, and other accounts without signing in to each one.
Your personal settings are synced to any Windows 8 and Windows RT PCs, including your themes, language preferences, browser favorites, and most apps.
You can get apps in the Windows Store and use them on up to five Windows 8 and Windows RT PCs.
If you're not signing in to Windows using your email address, that's okay—you can set up a Microsoft account at any time. For more info, see Create a user account.