Optical Tweezers are the widely accepted and applied tools in many fields of sciences, working on the concept of radiation pressure. Many types of optical tweezer system have been introduced till date and is still in process of development. Due to the ability to trap and manipulate the particles as well as living cells and organisms of sizes ranging from few microns to few nanometers without any structural damage to it leads to a wide range of applications of OTs. In this paper we will be discussing different methods/systems of optical tweezers developed for different applications over the years. This will give us the insight of working process and manipulations technique of conventional optical tweezer (COT) as well as recent developments of it.