A new Windows 10 feature coming in future phones called Continuum will turn your Windows 10 phone into a full PC.
Essentially this means that you will be able to connect a screen, keyboard and mouse to your Windows 10 phone and have the same experience as you would on a desktop. The Apps written for Windows 10 are developed to run across the various platforms such as PCs, tablets, convertibles, smartphones, and Xbox. Apps can automatically adapt to the screen size they’re running on.
The Apps will basically look like the full version of Windows 10 but everything is running from a Windows 10 phone.