Albedo
A material's base colour before any lighting — the fraction of incoming light the surface reflects, with no shadows or highlights baked in.
The word comes from the Latin albus, "white", and described the reflectivity of celestial bodies long before computer graphics. In physically based rendering the albedo texture is a material's pure base colour: brick is red, grass is green — without a single baked-in shadow or highlight. All lighting is then applied on top in real time.
That sets albedo apart from the old "diffuse maps", where artists often painted shading straight into the texture. Bake light into the albedo and it fights the engine's own global illumination, so the surface looks wrong as the light changes. A correct albedo is paired with separate maps for normals, roughness and metalness.