Text Source : Wikipedia
A vanishing point is a point in a perspective drawing to which parallel lines of objects appear to converge. The number and placement of the vanishing points determines which perspective technique is being used. The concept was first used by Renaissance artists such as Donatello and Masaccio.
linear perspective is a drawing with 1-3 vanishing points.
curvilinear perspective is a drawing with either 4 or 5 vanishing points, in 5 point perspective the vanishing points are mapped into a circle with 4 vanishing points at the cardinal headings N,W,S,E and one at the circle origin.
reverse perspective is a drawing with vanishing points that are placed outside the painting with the illusion that they are "in front of" the painting.
Vanishing points can also refer to the point in the distance where the two verges of a road appear to converge. This is often used to help assess the upcoming curves in the road; to judge the radius and therefore the entry speed and optimum line. If the vanishing point moves towards you or to your sides, the curve is tightening. If the vanishing point moves away from you or comes to center, the curve is straightening.