1 - About
There are two way (types) of representing an image:
|Raster graphics (also called bitmap)||dot matrix data structure. The image is defined in terms of rows and columns of individual pixels, each with its own color.|
|Vector graphics||geometrical primitives such as points, lines, curves. For instance, a single straight line is described in terms of its two end points.|
2 - Difference
The difference in these types of graphic images becomes readily apparent when a drawing is enlarged.
Most output devices display graphics as a raster or bitmap image. The real difference between drawing with bitmap graphics and vector graphics is the point at which the image is converted into a bitmap.
In the case of vector graphics, this conversion is done at the very last step before display, ensuring that the final image matches exactly the resolution of the output device.
3 - Scale
The bitmap image uses anti-aliasing, a method of using grayscale to attempt to smooth the drawing when the image is scaled up.