Classification of Docking by Flexibility Molecular docking is a prevalent computational method in structural biology and drug development. It is used to forecast the binding interactions of molecules, such as proteins and ligands. The flexibility of molecules, specifically proteins, is vital in influencing their ability to bind and selectivity. Three primary methodologies are typically utilised in molecular docking research to accommodate protein flexibility: ( ): (i) rigid docking, (ii) semi-flexible docking, and (iii) flexible docking (Figure ). Each methodology presents unique benefits and constraints, and the method selection relies on the research goals and attributes of the studied biological system. Every method forecasts the binding interactions among protein molecules using different approaches. While semi-flexible docking enables limited flexibility in some areas, rigid docking requires the absence of any changes in the shape of the protein structures. Conversely, flexible docking considers significant conformational changes in proteins and ligands during binding. Understanding the differences among these approaches will help one decide which is best for studying protein-ligand interactions ( ).