1. The problem is to understand and express the cube of the variable $g$, which is written as $g^3$. 2. Cubing a number or variable means multiplying it by itself three times: $$g^3 = g \times g \times g$$. 3. This operation is a common exponentiation expression in algebra, indicating the third power of $g$. 4. The final answer is simply the expression itself: $$g^3$$.