Heat transfer through porous media has gained considerable interest in recent years due to its ability to enhance the thermal performance in various engineering applications. There are two key advantages of using porous materials. First, the effective heat dissipation surface area is larger than that of traditional solid fins, which intensifies convective heat transfer. Second, the irregular motion of fluid around the internal porous structure improves mixing, promoting greater thermal uniformity by breaking the boundary layer and generating vortices, while in contrast, there is a drop in the pressure of the working fluid. This review provides a structured overview of the developments in heat transfer within porous media, focusing on two categories of working fluids: conventional fluids and nanofluids. Each category is further classified according to the flow regime involved: natural, forced and mixed convection. For conventional fluids, porous structures demonstrate considerable improvements in Nusselt number and thermal efficiency in compact heat exchangers and flow channels. For nanofluids, enhanced thermal conductivity and the possibility of coupling with magnetic fields (MHD) show promising results, especially under forced and mixed convection conditions. The findings from this review reveal that while both conventional and nanofluid systems benefit from the use of porous media, nanofluids exhibit superior heat transfer capabilities when properly optimized. Additionally, the effectiveness of porous media strongly depends on geometric properties, porosity, flow regime, and thermal boundary conditions. This paper offers a comparative understanding of these systems and identifies potential directions for future research in advanced thermal system design.