Computer illustration or digital illustration are visuals created entirely under digital tools and using some guiding devices such as tablets and mice that are under the control of the artist and use his own talent. It differs from "Computer Generated Art" (CG art), which are mathematical models created by the artist using a computer. There are two main tools used for digital illustration. Bitmap and vector. The most famous bitmap programs are Photoshop, Painter and Paintshop Pro. The most famous of the vector programs are Freehand and Illustrator. With the advancement of time and the development of digital media, many more programs and tools have been developed and made available to artists.