Below I have illustrated plans, sections and elevations of the custom-designed vanity pictured on the left.
The plan is a bird’s eye view looking down from three feet above the floor. I equate this to looking down at the top of a birthday cake.
Continuing with the birthday cake theme, a section would be like cutting into the cake and seeing all the layers.
The location of where the sections are cut is shown on the plan with a “cut line” and an arrow indicating where the cut has been made and which way we are looking at the section.
The elevation shows us what we would see standing in front of the vanity. The location/point of the view is again noted with a circle and arrow on the plan. Referring back to the birthday cake image, if you are looking at the side of the cake and it is a round cake, the drawing of this would be a rectangle. Vertical parallel lines are used as shading to show the curve.
The corresponding numbers in these circles, or "tags," tell us the drawing number and the drawing sheet/page in the set. The number on the top of the line indicates the drawing number on a sheet and the bottom number is the page or sheet number in the set. While these drawings all occur on one sheet, the principle remains the same for a larger set of documents where the drawings are on many sheets ... you match the “tag” numbers.