An ellipse is a curve where the sum of the distances from two fixed focal points is a constant. It is defined as the set of all points whose distances from two focal points add up to a constant. The standard equation of an ellipse is (x/a)^2 + (y/b)^2 = 1, where the focal points are located at (±c,0) and the vertices are located at (±a,0) and covertices at (0,±b). Examples are given of finding the focal points, vertices, and covertices of ellipses with given standard equations and of writing the standard equation of an ellipse given its focal points and constant sum of distances.