Spectroscopic methods relying on light sources play a crucial role in the identification of protein-ligand interactions. Such experimental techniques open doors for scientists to employ them in disease prevention, treatment, drug synthesis, identification of pathways contributing to different disorders, and unveiling the chemical structure of receptors within the human body. Furthermore, alongside experimental approaches, simulation methods also find utility. The combination of both experimental and theoretical techniques enhances the robustness of researchers' investigations. Conversely, the human body harbors a myriad of distinct proteins, each possessing its own distinct structure and functionality; the disruption of any one of these may lead to a range of ailments. Proteins within the human body have the capacity to engage with diverse ligands, yielding intriguing outcomes. Not only proteins interact with other proteins, but they also engage with pharmaceuticals and other substances within the body. Examination of the bonding types formed between the protein and the specific ligand can be effectively accomplished through optical spectroscopic techniques and simulation inquiries. This paper provides a comprehensive review of recent optical spectroscopy methods, as well as simulation studies, which are currently being employed by researchers in these investigations.