The document discusses coordinate geometry and the coordinate plane. It explains that the coordinate plane uses two perpendicular axes, the x-axis and y-axis, to uniquely locate points in space. Any point on the plane is identified by an ordered pair of numbers representing its distance from each axis, known as rectangular coordinates. Positive values are above and to the right of the origin point where the axes cross, and negative values are below and to the left. Together the two coordinate values precisely define the location of a single point.