Best way to describe vector vs raster

I always say

Raster records the pixels in the picture.

Vector records the steps it took to draw the picture.

So if you enlarge Raster you get a big picture with big pixels. If you enlarge Vector the computer follows the steps to redraw at higher resolution.

---

If you have a chance to demo it for them, load up Word and put in 1 small (raster) image and 1 clip art. Then drag the corners to show what happens. You could even print out the before/after and hang it on your cube so you have something to point to.

In layman's terms.

Raster (I usually just say "bitmap" though) images record the colors in order. Blue, blue, blue, light blue, light blue, light blue... (At this point i'm pointing at a nearby object and reading colors on the top, left to right).

Vector image is a description about an image. "A light blue circle 12cm across. A solid blue background.

Then I explain how Rasters are better for photographs because that's how cameras and scanners see the image anyway, and Vectors are better for illustrations because you can make it any size without losing detail.

Vector graphics are to the etch-a-sketch, as raster graphics are to a mosaic.