The classification of docking by search space is the grouping of docking techniques depending on the extent of the search area taken into account during the docking procedure. Understanding the attention and computing needs of several docking techniques depends on this classification. This classification has two main categories: (i) Local Docking, which limits the search area to a particular region or binding site on the protein, and (ii) Global Docking, which looks over the whole surface of the protein to find possible binding sites and binding poses ( ) (Figure ). Local docking: Local docking requires a binding site and search space from a userdefined one (Figure ). There are two main approaches to defining a location for local docking: (i) experimental ligand binding sites and (ii) theoretical predictions. (i) Experimental techniques capture the location of small natural molecules on targets as a binding site. Small natural molecule binding sites are called ligand binding sites (LBSs) ( ).