what is group
In mathematics, a group is an algebraic structure consisting of a set of elements together with an operation that combines any two elements to form a third element.The operation satisfies four conditions called the group axioms, namely closure, associativity, identity and invertibility.One of the most familiar examples of a group is the set of integers together with the addition operation; the addition of any two integers forms another integer.nformally, a subgroup is a group H contained within a bigger one, G. Concretely, the identity element of G is contained in H, and whenever h 1 and h 2 are in H, then so are h1 â¢ h2 and h 1 â1, so the elements of H, equipped with the group operation on G restricted to H, indeed form a group.