What are villi and what makes them suited for their function?

Villi are finger-like projections.They increase the surface area of inner walls and helps alot in absorption of digested food.

Explanation:

imagine a line passing through the center of earth that goes through both the north pole and the south pole. this imaginary line is called an axis. earth spins around its axis, just as a top spins around its spindle. this spinning movement is called earth's rotation. at the same time that the earth spins on its axis, it also orbits, or revolves around the sun. this movement is called revolution.