A hyperbola is the set of all points in a plane such that the absolute value of the differences of the distances from two fixed points, called the foci, is constant. Every hyperbola has two axes of symmetry. One runs through both foci, known as the transverse axis, while the other, perpendicular to the first, is equidistant from both curves, called the conjugate axis. For this hyperbola the transverse axis and conjugate axis are the x-axis and y-axis, respectively.

In this graph the transverse axis runs horizontally. There are also vertical hyperbolas, where the transverse axis is vertical. The following table details the properties of both types of hyperbolas.

Property	Horizontal Hyperbola	Vertical Hyperbola
General Equation	(x-h)^2/a^2-(y-k)^2/b^2=1	(y-k)^2/a^2-(x-h)^2/b^2=1
Transverse Axis	Horizontal	Vertical
Vertices	(h ± a, k)	(h, k ± a)
Foci	(h ± c, k)	(h, k± c)
Asymptotes	y-k = ± b/a(x-h)	y-k = ± b/a(x-h)
c-value	c^2=a^2+b^2	c^2=a^2+b^2

Although these curves are not considered to be parabolas, they do have foci and directrices.