MOUSE-POWERED SCULPTURE
Whether you use a stylus or a mouse, there are two ways of drawing an image on your computer. Bitmap painting and vector drawing.
Let's face it, both are easiest with a tablet and stylus. Vector drawing is marginally easier with a mouse. But if you're going to do much painting on your desktop computer, if you're anything like me you'll find a graphics tablet will transform a frustrating chore into a delight. Drawing on a touch screen phone or PDA is even easier. Pick up your screen and scribble on it just like a notepad.
But what exactly is this difference between computer painting and computer drawing?
When you're painting, you lay down the pixels one by one like a tapestry.
When you're vector drawing, you click and drag to make lines, shapes and fills which are recorded mathematically.
Computer painting and drawing are two quite different experiences
With vector drawing, instead of tracing a fine line, you're dotting down points and pushing and pulling at little handles to alter angles. That's why it's not too difficult to do with a flat-footed mouse.
Vector drawing feels more like sculpture than painting.
WHAT'S WORRYING THIS OWL?

Vector drawing may be less frustrating to do with a mouse than bitmap painting, and may even have been evolved with that blunt instrument in mind. But sometimes you can get some strange results...
To find out what it really feels like to do vector drawing, try playing the face game if you have a Pocket PC - and find out how the bald owl lost part of his costume. (By the way, if you think you can't draw, remember you've been able to do symbol drawing ever since you could wield a crayon.)
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Pocket PCs use vector type processes for handwriting recognition. Vector drawing is included in many office programs like Word and Excel. Graphics tablets and styli aren't too common in an office setting, but vector graphics are good for lettering, diagrams and charts you can fix with a mouse.
Major desktop paint and photo apps like Photoshop and Painter are bitmap editors. They handle photos and provide inspiring simulations of art materials. However, they also allow you to do some vector drawing. Even if you have the latest Wacom tablet, this is still handy for making circles that don't look like potatoes, squares that are square, and fancy type.
Vector artwork can look a little stilted, but it does stay sharp at any magnification, since it's recreated every time it's shown. Unfortunately, you lose this advantage when you're making most very small pictures. Icons, wbmp, gif and jpeg images are saved as bitmaps, no matter how they were made.
detail on the difference between
bitmap and vector drawing with stylus or mouse
Pocket Pictures - Gif or Jpeg? - Draw or paint?
You can still make bitmap GIF pictures pretty small with Photoshop Save for Web
Computer art editors. Stylus or mouse?