1. The problem is to simplify or understand the expression $\left(\;\right)\frac{4}{3}$. 2. Notice that $\left(\;\right)$ represents an empty set of parentheses, which means it does not affect the value of the expression. 3. Therefore, the expression simplifies directly to $\frac{4}{3}$. 4. The fraction $\frac{4}{3}$ is already in its simplest form because 4 and 3 have no common factors other than 1. 5. So, the final answer is $\frac{4}{3}$.