I have recently started making my own clip art, and the difference between raster and vector images is really important. Raster images are made from pixels, so when you zoom in on them, you can see the pixelated image, which appears fuzzier to the eye. While not always as detailed as a raster image, a vector image can be scaled and resized without giving off the dreaded pixelated effect. A vector image is made using basic computer geometry — shapes!
Here is a clip art image I made of a school girl with moppish hair giving off Little Orphan Annie vibes:
