Researches on the improvement of heat transfer using nanofluids, ionanofluids, and nanofluid assisted devices have gained significant attention worldwide since the previous decade due to their remarkable properties. However, there are many difficulties in preparing a stable nanofluid and integrating it for practical applications to increase the dissipation of heat from any thermal systems. Even though there are some reviews on nanofluids and nanofluid assisted heat transfer devices separately, an attempt has been made to analyze the latest researches on nanofluids and ionanofluids that lead to an important discussion to enhance the thermal performance of a system. In this paper, we summarized the preparation, thermophysical and hydrothermal properties, mechanisms, factors responsible for obtaining stable and enhanced thermophysical properties furthermore and its benefits on integration with heat transfer applications. The present study compiles theoretical and experimental studies from researchers investigating on stable nanofluids and ionanofluids, incorporating their effects on heat transfer applications.