Tileset

A Tileset is a collection of tiles which follow a common theme. They allow you to select from a list of different tiles (each with varying sizes) so that you can construct an area to use in your module

Neverwinter Nights 2 will have a fundamental change in how environments are built. Traditioally, all areas were built with tilesets from a list (NWNWiki: NWN Tileset). NWN2 will use tilesets for interior areas only while exterio areas will be built with a brand new method using height maps and paintable textures.

Currently Obsidian has confirmed Cavern, and Tavern tilesets. While these names are unofficial, they give the general idea what they will be used for.