I'm a doctor, not a mechanic

From Unreal Wiki, The Unreal Engine Documentation Site

Modding in Unreal is the process of leveraging the existing Unreal engine which ships with a toolset and enables licensed owners of the software to produce their own levels.

Modding levels is an activity which is promoted by Unreal Technologies with contests such as "Make something Unreal".

In addition to making a level with basic geometry, decorating it with a variety of textures, meshes, and lighting, the toolset also allows editors the ability to use scripting and even produce custom gametypes.

This can be a great way to prototype or demonstrate 3d designs.

There are different versions of the Unreal toolset, so those getting started need to be aware of that there is more than one version.

There are books and tutorials published on the topic as well as academic research on the process of modding levels. There are successes with "Serious Games" and there are members of the International Game Developers Association (IGDA) which promote the use of Unreal level modding to provide an example of dedication by budding or aspiring game designers.

End game assets may be developed using a variety of 2d and 3d software products.

The Unreal Engine and level modding has been adopted within the academic environment including University, Community collge, and at least one vocational technical high school.