ImageMagick and GD are software libraries which should be present on a web server to enable images to appear on a given website. They enable you to perform a variety of tasks with the images - create, flip, resize, change colors, etc. These things can be done online and in real time, so if you include a static image, for instance, the libraries make it possible for a thumbnail to show up on the site or for the image to be resized automatically based on the device and resolution the visitor is using. Both ImageMagick and GD can be used with various web programming languages like PHP, Perl and Python, so you do not have to stick to a single language to create your internet site. They work with more than 100 formats, including the most frequently used ones - JPEG, GIF, TIFF, PNG, and so on.