The parabola is the locus of points on the plane that is equidistant from a fixed point called the focus and a fixed line called the directrix.
Elements of the Parabola
The focus is the fixed point F.
The directrix is the fixed line d.
The focal parameter is the distance from the focus to the directrix. It is denoted by p.
The axis is the line perpendicular to the directrix that passes through the focus.
The vertex is the point of intersection of the parabola with its axis.