Hyperbolas are defined by the difference between distances to two fixed points called foci. A hyperbola consists of all points where this difference is a constant. It has two branches, two vertices, and two asymptotes which are the diagonals of an invisible box defined by the hyperbola's x-radius and y-radius. To graph a hyperbola, one puts its equation into standard form to determine the center, radii, and direction of opening, then draws the corresponding box and curves.