Albedo

An albedo (sometimes diffuse map) is a texture containing view-independent color information.

An albedo (sometimes diffuse map) is a texture containing view-independent color information. It is what we normally think of a texture as being, as opposed to 'treatment' textures like bump maps or specular masks.

Albedos are referenced in materials with the $basetexture command.

Source: https://developer.valvesoftware.com/wiki/Albedo