Mods can be an inroad to the game industry in some cases, if a project catches the attention of the original developer or some other professional studio. Mods are distinct from user-generated content because they are not created or distributed with tools built into the game itself, like Halo's Forge.
A modification (or mod) is an unofficial add-on for a game that adds new things, changes things already in the game or completely overhauls the gameplay and creates a new experience.
