Adobe illustrator 10 Manuale Utente

Computer graphics fall into two main categories—vector graphics and bitmap images. 
Understanding the difference between the two helps as you create, edit, and import 
artwork. 

In Illustrator the type of graphic image can have important effects on your workflow. 
For example, some file formats only support bitmap images and others only vector 
graphics. Graphic image types are particularly important when importing or exporting 
graphic images to and from Illustrator. Linked bitmap images cannot be edited in 
Illustrator. Graphic formats also affect how commands and filters can be applied to 
images; some filters in Illustrator will only work with bitmap images. 

Drawing programs such as Adobe Illustrator create vector graphics, made of lines and 
curves defined by mathematical objects called vectors. Vectors describe graphics 
according to their geometric characteristics. For example, a bicycle tire in a vector graphic 
is made up of a mathematical definition of a circle drawn with a certain radius, set at a 
specific location, and filled with a specific color. You can move, resize, or change the color 
of the tire without losing the quality of the graphic. 

A vector graphic is resolution-independent—that is, it can be scaled to any size and 
printed on any output device at any resolution without losing its detail or clarity. As a 
result, vector graphics are the best choice for type (especially small type) and bold 
graphics that must retain crisp lines when scaled to various sizes—for example, logos.

Because computer monitors represent images by displaying them on a grid, both vector 
and bitmap images are displayed as pixels on-screen.

Vector graphics are good for reproducing crisp outlines, as in logos or illustrations. They can be 
printed or displayed at any resolution without losing detail.