rectangular coordinate system

A fixed coordinate system that defines the location of all graphic items in a drawing. A coordinate system uses an origin point and X (horizontal) and Y (vertical) axes. Coordinates on the right side of the X axis and top portion of the Y axis have positive values; coordinates on the left side of the X axis and bottom portion of the Y axis have negative values. Points on the coordinate system reflect the drawing's measurement unit and are specified by listing the X coordinate and then the Y coordinate, such as (X, Y). For example, a coordinate pair of (100.00, 200.00) for a drawing measured in centimeters represents a point that is 100 centimeters on the X axis and 200 centimeters on the Y axis.