A model is a 3D object. Models for OpenArena are usually created with Blender and are in MD3 format. Models can be placed inside maps (for example, as decorative elements), or it is even possible to work on a map as a model (see Modelling a map). Models placed inside any official OpenArena map have to be included and released under the GPLv2 (or Public Domain) license, like everything else (see DeveloperFAQ#License).
From the point of view of the final user, the most interesting kind of models are the character models, also known as player models, and often simply referred as models.
A "model" is a complete 3D character; while a "skin" is simply a texture variation (different colors). More skins can fit the same model.
You may be interested to:
- Select a model/skin: Manual/Player settings#Model
- Add a model designed for Quake 3 Arena: FAQ#How can I use maps, models, mods made for Quake 3 Arena?
- Know about the OpenArena characters: Manual/Characters, Characters, PlayerMDLs
- Create a model: Modeling, Making a player model, Creating a player model in Blender, MD3 format
- Other: Character ideas, Pak0.pk3/Models, Manual/Graphic options#Force player model, IffyContent