It's an identification number that will uniquely identify something. The idea being that id number will be universally unique. Thus, no two things should have the same uuid. In fact, if you were to generate 10 trillion uuids, there would be something along the lines of a .00000006 chance of two uuids being the same.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…