**Definition**: A non empty set G having binary operation “*” (say) is called **semi group** in math if it satisfies the following two axioms:

**Closure Property w.r.t “*“**

i.e, a\ast b\in G\;\;\;\;\;\;\;\forall\;a,b\in G

**Associative Law w.r.t “*“**

**Examples of Semi Group:**

- The set of
**W- {0,1}**with respect to “Addition” and “Multiplication”. - The set of
**Natural Number**with respect to “Addition”. - The set of O^+ with respect to “Addition”.