You will note that if you open an Unreal Engine game project in Visual Studio you will be presented with the following build options:
The editor build can be attached to and loaded to the Unreal Editor. There is off course some overhead associated with this.
The non-editor bulds are stand alone builds that you can run out of the editor. To run these builds you would need to cook content for the given platform in the editor through File-> Cook content for [Platform].
The debug game options are the least optimized and allow access to all variables during debug, while the development options are semi optimized and the shipping option is fully optimized.
The shipping build is the actual game you distribute for a given platform. This has full optimization on no debugging features.
The unreal editor has a compile option that will create new binaries for a DevelopementEditor build.