ImageMagick and GD are software libraries that ought to be present on a web server for images to appear on a given website. They enable you to execute a variety of tasks with the images - create, flip, resize, change colors, etcetera. These things could be performed online and in real time, so if you add a static image, for example, the libraries make it possible for a thumbnail to show up on the internet site or for the image to be resized automatically depending upon the device and resolution that the website visitor is using. Both ImageMagick and GD can be employed with many different web programming languages including PHP, Perl and Python, so you don't need to stick to a single language to build your website. They work with over a hundred formats, which includes the most popular ones - JPEG, GIF, TIFF, PNG, etc.