Delivering a common experience across multiple devices requires more than just an operating system that can handle mouse-and-keyboard or touch commands. To be able to move seamlessly from one device to another, you have to make sure all your apps and data are accessible across each device. Just a few years ago, that would require you to save data to some form of removable data storage and transfer it physically to another machine.
Microsoft made a shift to the cloud with Windows 8. The cloud is a general term for networked computers that store data and applications on them. Saving data to the cloud means that you can access the information with any gadget capable of connecting to the cloud network.
In Windows 8, a user must create a profile that includes access to Microsoft's cloud network. Signing on from any Windows 8 device will give you access to your apps and data as if it were your primary machine. Windows 8 apps run directly on user devices. That means that signing into a Windows 8 machine with your account will give you access to your apps, but you'll have to download them to the machine first.
For people who are particular about their OS settings, Windows 8 cloud synchronization is a welcome addition. Setting features like desktop themes, language and preferred browser on one Windows 8 device creates the foundation. When you log in from a different Windows 8 device, the OS applies your preferences from the other machine. This even applies to browser history, so if you want to show someone that funny cat video you looked at on a completely different computer, you still have that option.