There are two main file formats used in typical graphic design,
they are bitmap graphics and vector graphics.
and image-editing software, such as Adobe Photoshop or Corel
Photo Paint, generate bitmap images which use a grid of small squares,
known as pixels, to represent graphics. Each pixel in a bitmap image
has a specific location and colour value assigned to it. For
a windmill in a photo is made up of a collection of pixels in that location,
with each pixel part of a mosaic that gives
the appearance of a windmill.
Artwork guidelines - file types explained.
When working with bitmap images, you edit pixels rather than objects
or shapes. Bitmap images are the most common electronic medium
continuous tone images, such as photographs or images created in
painting programs, because they can represent subtle gradations
shades and colour. Bitmap images are resolution-dependent.
This means that they represent a fixed number of pixels and as a
they can appear jagged and lose detail if they are scaled
on-screen or if they are printed at a higher resolution than they were
Drawing programs, such as Adobe Illustrator or Corel Draw, create
vector graphics which are made of lines and curves
mathematical objects called vectors. Vectors describe graphics
according to their geometric characteristics. For example,
drawn as a vector graphic is made up of a mathematical definition
of shapes drawn with a certain height and width, set
at a specific
location, and filled with a specific colour. You can move, resize, or
change a colour of the windmill 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
losing its detail or clarity. As a result, vector graphics are the best
choice for type (especially small type) and bold graphics
retain crisp lines when scaled to various sizes.