Albedo is a measure of reflectance, i.e., the fraction of incoming light that is reflected. The Earth's albedo varies over the Planet and conditions: water versus land, snow cover, cloud cover, city versus country, forest versus desert.
The general albedo of a planet or Moon can be inferred from calculated incoming versus observed outgoing Electromagnetic Radiation, and provides clues regarding its material and Atmosphere.
Albedo Features are regions on a planet or moon with a noticeably higher or lower albedo than their surroundings. Mars and Mercury show such features.