What is Vector Graphics? Vector Graphics or Bitmap Graphics?
Vector graphics (also called geometric modeling or object-oriented graphics)
is the use of geometrical primitives such as points, lines, curves, and polygons,
which are all based upon mathematical equations to represent images in computer
Vector graphics is an alternative to raster graphics, which is the representation
of images as an array of pixels, as it is typically used for the representation
of photographic images.
Advantages to this style of drawing over raster graphics:
This minimal amount of information translates to a much smaller file size
compared to large raster images (the size of representation doesn't depend
on the dimensions of the object), though a vector graphic with a small file
size is often said to lack detail compared with a real world photo.
Correspondingly, one can indefinitely zoom in on e.g. a circle arc, and
it remains smooth. On the other hand, a polygon representing a curve will
reveal being not really curved.
On zooming in, lines and curves need not get wider proportionally. Often
the width is either not increased or less than proportional. On the other
hand, irregular curves represented by simple geometric shapes may be made
proportionally wider when zooming in, to keep them looking smooth and not
like these geometric shapes.
The parameters of objects are stored and can be later modified. This means
that moving, scaling, rotating, filling etc. doesn't degrade the quality
of a drawing. Moreover, it is usual to specify the dimensions in device-independent
units, which results in the best possible rasterization on raster devices.
From a 3-D perspective, rendering shadows is also much more realistic
with vector graphics, as shadows can be abstracted into the rays of light which
form them. This allows for photorealistic images and renderings.
Source - Wikipedia.org