From TorqueWiki

[edit] What can a Game Engine (GE) like Torque (TGE) do for you?

It display amimated, interactive 3D Graphics.

What is the difference to OpenGL or DirectX?

A GE does more:

• control user input in a Platform independent way
• import models and animations
• import world geometry including zones, portals and collision geometry
• Terrain, atmosphere and (dynamic) sky.
• manage resources in a scene graph
• simulate time
• build a 2D GUI (Head-UP display) on top of the 3D scene
• 3D Audio, incorporated into the scene-graph
• tools: World Editor, Terrain Editor, Light-Tool, GUI Editor, etc. (TGE comes with a number of tools).
• networking
• Scripting language and interpreter
• physics
• AI