There are two types of user account you can use to sign-in to Windows 8 - Local accounts and Microsoft accounts
Local Account:-
•A basic account consists of a username (and if required a password), and can only be used to log on to the computer it was created on
•You will have to sign-in into additional Microsoft services (i.e. Windows Store, Skype, OneDrive etc) separately
•Photos and documents won't be automatically stored in the cloud (OneDrive)
•Settings will not be synced between all your Windows 8 devices
Microsoft Account:-
•A Microsoft account allows you to sign-in with your email address and password - If you already use services such as Skype, Xbox, Outlook.com (previously called Hotmail), Windows Live or OneDrive then you already have a Microsoft Account and can use this to sign-in to your Windows 8 computer
•Allows you to use the same sign-in on all your Windows 8 devices
•Settings (such as start screen layout and appearance, desktop personalization, app settings, internet history and favorites, language/keyboard/mouse settings) can be configured to follow you to any computer - so all devices you use will look and behave the same
•Automatically connects you to your OneDrive account, and other Microsoft services such as Skype and the Windows Store without having to sign-in separately
•All documents/photos are automatically stored in the cloud (OneDrive) so you can easily access them on all of your devices
So in summary if you are using other Microsoft services and want to make full use of your new computer then it is better and easier to use a Microsoft account to sign-in, then you can have access to everything you need without having to sign-in separately every time you want to download from the Windows Store, use Skype or any other Microsoft apps
Creating a New User Account
You can create user accounts in Windows 8 by opening up PC Settings and clicking on Accounts > Other accounts and then Add an account
If you already have a Microsoft account you can sign-in, if not you can create a new one or choose to sign-in without a Microsoft account (i.e. use a local account)
At this point you will also have the option to specify if this new account is for a child to use - if so then Family Safety features will automatically be enabled
If you choose to use a Microsoft account then you will also see a prompt explaining that all your documents, settings and photos from your camera will be saved to OneDrive by default - these settings can be changed later from the OneDrive settings as explained here
Converting Local Account to Microsoft Account
If you currently sign in using a local account, then you can easily change it to a Microsoft account at any time
Open up PC Settings and go to Accounts > Your account, then click on Connect to a Microsoft account
You will then be asked to enter an existing Microsoft account email address and password - or you can click Create a new account if you don't already have one
P.S. You can also convert from a Microsoft account to a Local account if required, this is done in the same way as above, but this time you click on Disconnect
Choosing What Items Are Synced With a Microsoft Account
You can choose what settings will be synced with your Microsoft account by opening PC Settings and clicking on OneDrive > Sync settings