What is the difference between Paint programs (technical name: raster graphics painting) and Draw programs (technical name: vector graphics drawing)?
In Paint programs, images are represented by bits.
The shapes cannot be manipulated as separate entities. They can only be changed by modifying individual pixels with a tool. Text is not editable.
When images are scaled up, the same pixels get bigger and resolution is reduced.
Programs that are raster based include Photoshop and MacPaint. Tools typical of paint programs are paintbrush, spraycan and eraser.
In vector graphics, objects, such as lines, curves, shapes or text, are based upon mathematical formulae.
Software programs that exclusively allow the creation and manipulation of vector graphics are called 'draw' programs.
Programs that are vector based include Adobe Illustrator and MacDraw. Illustrator uses Bézier curves based on a formula devised by Pierre Bézier. Tools typical of draw programs are pencil and pen.
When vector images are scaled up, resolution is not affected, because the formulae determine where the pixels go for the best image display.
Enlarging a vector image (left) scales up the shape with no loss of quality.