A monomial is an algebraic expression with only one term. Monomial expressions involve the multiplication or division of numbers and variables in some valid combination. $$\begin{array}{cc}{z}^5& ✓\\ & \\ 2x& ✓\\ & \\ \frac{\text{-}7y{z}^4}{2}& ✓\end{array}$$ Note, the exponents of the variables in a monomial are whole numbers and a monomial cannot have variables in its denominator. $$\begin{array}{cc}{m}^{\frac{4}{7}}& \times \\ & \\ g^{\text{-}3}& \times \\ & \\ \frac{1}{x}& \times \end{array}$$ When multiple monomials are put together, separated by $+$ or $-$ signs, they are the terms that form polynomials.