Magneto Rheological Fluid (MRF) is a smart material as their rheological property can be restricted by an externally applied magnetic field. MRF consists of base oil in which ferromagnetic particle namely carbonyl iron powder is dispersed uniformly. This has enabled to control the viscosity of the fluid instantly and reversibly thereby making it a very potential semi active suspension application and torque transfer devices. The current paper focuses on recent developments of MRF as s suspension and torque transfer devices. The influence of the ingredients (carbonyl iron powder and additives) on the damping effect and its applications are discussed. The squeeze and shear mode of operations are elaborated, and mono-tube and twin tube design parameters involved are discussed extensively along with the applications. Different types of MRF clutches as well as, torque, design and applications of MRF clutches are also discussed. A summary of research work related to MRF is made.