Solar thermal collector is a simple, economic, and environment friendly equipment which is used to utilize solar energy for various agriculture and industrial applications. The investigators mainly focus on the improvement of the thermal performance by providing various fins shapes underside of the absorber plate in the single pass and double pass solar thermal collector. This work discusses the influence of different shaped fins used by various researchers in improving the thermal performance of thermal collectors. Fin’s design, geometries used, and their influence on turbulence and thermal performance have also been discussed. As per the literature review and comparative study the heat transfer rate is greater for solar air thermal collector with fins as compared to solar air thermal collector without fins.