The functional ability of any device lies in its actual thermal management. To augment heat transfer, it is very crucial to identify the best heat transfer liquid available. The field of nanofluids plays a phenomenal role in devices that emit heat during their operation. Nano-sized particles are scattered in base fluid, which then becomes nanofluid for the first time since it was invented in the late twentieth century. A nanofluid synthesized by dispersing two kinds of nanoparticles is called a hybrid nanofluid. These are blended using mechanical stirring, ultrasonication, and surfactants to improve their physical potential. The main reasons the nanofluids work so well are because of their improved stability, pH control, and thermophysical qualities, and they will be used for different thermal applications. The current review is concentrated on nanoscale-level particles used in the synthesis of nanofluids and thermal applications such as electron cooling, heat exchangers, and radiators. The present review of nanofluids summarizes some researchers’ progress and discusses challenges and the future scope of nanofluids. Finally, it is concluded that hybrid nanofluids will be synthesized commercially on a large scale and used as next-generation heat transfer fluids for various applications.