Paint or Bitmap Bitmap tools are designed to create images by emulating some of the techniques used in traditional painting, airbrushing, and drawing. The software operates directly on the dots which make up the image. Changes to these dots are required to change the image. Newer and more sophisticated paint tools allow the use of layers, transparencies, and other techniques for manipulating the dot pattern and color information. The number of colors available is listed as the bit depth.
Bit depth is in binary notation.
The number of bits is the exponent for base two. Twenty-four bit provides 16.7 million colors. More of each will produce a larger file. Files are stored as a pattern of dots with color information for each dot. Dots on a computer screen are called pixels.