An ellipse inequality describes a region on a coordinate plane where the points satisfy the condition of being inside or outside an ellipse. An ellipse is typically defined by a standard equation in the form of $$\frac{(x-h)^2}{a^2} + \frac{(y-k)^2}{b^2} \leq 1$$ for points inside or $$\frac{(x-h)^2}{a^2} + \frac{(y-k)^2}{b^2} \geq 1$$ for points outside, where (h, k) is the center, and a and b are the lengths of the semi-major and semi-minor axes. Understanding ellipse inequalities allows for the analysis of geometric relationships and regions formed by quadratic equations in two variables.