Composed of line, circles, and arcs. Smaller file because a line is defined by the start and length 2. Infinite zoom ability because line width is not defined by display. More complicated to construct. Ultimately, precision is annoying.
Straight lines are straight.
They exist along the x and y which meet at right angles to each other. Drawings which the x and y axis cross at 135 degrees. C. 2d drawing. A two dimensional drawing has lines along the x and y axis. Three dimensional drawings use the x,y,z axes to create positions in 3D. D. Drawing scale.