Running two apps side by side IN WINDOWS 8

Any app can be pinned to the left or right-hand side of the screen. For example, 

open the People app and then press the Windows Key + . (period) to move 

that app to the right-hand side of the screen, pressing the same keys again will 

move it to the left-hand side, and pressing the same keys again will make it full 

screen. While an app is pinned, any other app or program can be opened and 

loaded into the available space on the screen. For example, in the below picture, 

we've opened a browser window and have the People app running to monitor 

our social networks.
Windows 8 People
Any open app can also be pinned using your mouse by clicking at the top of the 

tile and dragging it to the left or right-hand side of the screen.
 

Bonus tip: The Desktop can also be pinned to the left or right-hand side of the 

screen.
 
Note: In order for snap to work properly your resolution must be at least 1,366 x 768.