Adobe ILLUSTRATOR 6.0, Online Manual, Page: 628 / 893

628
Paint and image-editing software, such
as SuperPaint and Adobe Photoshop,
generate a different type of electronic
artwork known as bitmap images, also
called raster images. Computer displays
and printers are called raster devices
because they present information with
a raster, or grid of dots. The raster is a
sequence of lines, and each line is a row
of dots called pixels (picture elements).
Raster devices can be characterized by
their
resolution in dots-per-inch (dpi).
Many Macintosh monitors, for example,
display information at 72 dpi, while
most laser printers print information at
300 or 600 dpi.
Because vector artwork is represented
mathematically as lines and curves,
software must convert vector artwork to
pixels to display the artwork on a moni-
tor or to print the artwork on a printer.
Converting vector artwork to pixels is
called rasterizing the artwork.