Final answer:
A hyperbolic paraboloid is a surface created by moving a downward curving parabola along another upward curving parabola, forming a saddle-shaped figure.
Step-by-step explanation:
The surface formed by moving a vertical parabola with downward curvature along and perpendicular to another parabola with upward curvature is known as a hyperbolic paraboloid. This type of surface resembles a saddle shape, as it is concave in one direction and convex in the other. It can be seen in various structures and designs due to its unique and aesthetically pleasing shape, and it's mathematically significant as an example of a doubly ruled surface.