The Gamedata is composed from functional compiled data that would be ready to be shipped with the mod. The data is loadable by the engine.
The Rawdata contains all the source scenes, textures, materials, maps(vmf), sounds used to produce the gamedata.
The Data Pipeline describes how it is all tied together.

Here is the TDP Rawdata located in "C:\troydp" :



Here is the TDP Gamedata located in "C:\Program Files\Valve\Steam\SteamApps\SourceMods\troydp" :