The given expression is a product of two binomials: (2x + 3y) and (2x - 3y). This is a special product known as the difference of squares. The formula for the difference of squares is: $(a+b)(a-b)=a^2-b^2$. Here, a = 2x and b = 3y. Applying the formula: ${\left(2x\right)}^2-{\left(3y\right)}^2=4x^2-9y^2$.

Final Answer: 4x² - 9y²