Two games job roles

Level Editor:
A level editor designs different portions of a game, this could be from a level in a traditional gaming sense, to open world spaces and interiors of buildings. The design process sometimes involves mapping out what the player would experience.
 Level editors sometimes need to be able to use 3D modelling programs such as 3D Studio Max or Maya to test and work out different design ideas and processes. However in larger companies this is often not the case, with specific people working on the 3D side. Often larger companies will have their own software for level creation, for example construction kits.

3D Modeller/ Artist:

A 3D modeller will use concept work to create a 3D version which can be used within the game itself. This could range from characters and enemies, to trees and landscapes. Similar programs are required to create the models, such as 3D Studio Max and Maya.