DefinitionGroup theory is the study of algebraic structures in abstract algebra called groups. A group is a set with a binary operation which combines any two elements to form a third element. Every group must be subject to four conditions called “group axioms”, namely closure, associativity, identity and invertibility. A group theory is a method to represent algebraic terms and the perumutation of base structures, and symmetries and added structures in the study of various fields like physics, chemistry and mathematics. The group theory is of fundamental important in the study of abstract algebra and number theory. Example: The set of integers Z with addition is a group, it has a identity 0 and all of its elements have inverses, ie. the negative of all elements.