We present a review of the basic operating principles and measurement schemes of standalone and hybrid distributed optical fiber sensors based on Raman and Brillouin scattering phenomena. A well-known example is RADAR, and more. Distributed Optical Fiber Sensing (DFOS) transforms standard fiber optic cables into powerful sensors capable of detecting temperature, strain, and acoustic signals at thousands of measurement points over long distances. For example an acoustic/mechanical wave generates a dynamic density variation; such a variation may be affected by local.