Viewing Unreal engine environments

Real newbie question.
How does a person who does not have the program unreal engine 4 loaded on their computer view and move thru an Unreal 3d Environment? Also, what format is this exported out of Unreal?

When you’re finished designing a project you build the final game, you’ll end up with a .exe file which is the game program and then you’ll have a folder of other assets and files that are required to run it, all you have to do is open that program file to run what you created.