There are two main types of Viewports in Unreal Editor: Perspective and Orthographic. The perspective view is a
3D window into the game world. The Orthographic views - Front, Side, and Top - are 2D Viewports that each look
down one of the main axes (X, Y, or Z).
You can cycle through the types of Viewports by pressing Alt and G, H, J, or K. These set the
Viewport to be Perspective, Front, Side, or Top, respectively.