Vibration signals indicate machine?s health. In most of the cases, it stipulates the requirement of bringing down vibration intensity to operational limit. Researchers are focusing over different types of vibration isolators and their optimization in terms of space occupancy,weight, cost and reliability. In this paper, an attempt has been made to introduce the basic concepts of Magnetorheological Fluids (MRF) which can be used as a semiactive vibration isolator, for the beginners and researchers. The scope of MR fluids in future, problems are also presented.