|Drawing for the artistically skill-less|
As far as I understand it, there are two main image types: rasters and vectors. Most people have experience drawing with rasters. This is like doodling on a digital picture of your ex-boyfriend's face. “Cutting” you out of a picture and putting you in front of the Grand Canyon although you’ve never been there. The major difference is that when you “stretch” raster images the quality of the picture will deteriorate and look blurry mess. Vector art (mathematics!) is created with lines, shapes and data so when you stretch it, everything is proportionally increased. This allows you to make things as big or as small as you like!