Heat transfer is a very important process used in the industries, especially in process industries where the raw material is subjected to various processes so as to convert it into finished products. To achieve better heat transfer efficiency of the heat exchanger, maximum heat transfer should take place within the operating temperature range of the fluids in the heat exchanger. The researcher has made an effort to improve the heat transfer rate between two fluids. They have been developed various heat transfer enhancement techniques to improve the heat transfer rate by considering various factors that affect the heat transfer rate such as temperature, the velocity of fluid, turbulence, surface area subjected to heat transfer, etc. These techniques can be classified as active techniques and passive techniques. Active techniques are those who require a power supply for the operation while passive techniques are those who do not require any external power supply for the operation. This paper presents a review of various heat transfer enhancement techniques so that they can be chosen into the industry as per the requirement and according to their relative merits.