2.6.1Introduction to Molecular Docking2.6.1.1 Biological BackgroundMolecular docking is used to predict the structure of the intermolecular complex formed between two or more molecules. The most interesting case is that of protein-ligand interaction, due to its applications in medicine. The ligand is a small molecule that interacts with protein binding sites. Binding sites are areas of proteins known to be active in compound formation. There are several possible mutual conformations in which bonding can occur. These modes are commonly called binding modes.2.6.1.2 Physics