Ripe (Shu) Pu'er tea starts out as raw (sheng) pu'er, but then goes through a deliberate “post fermentation” process to mimic and accelerate the kind of changes that happen in sheng pu'er from a period of many years to six weeks.
The outcome is earthy and smooth, but with a leathery, compost, barnyard character (and we mean this with sincere flattery) that some find to be an acquired taste.