- The GIF image format is widely used on the World Wide Web. It was initially used by Compuserve to compress images for display on its online services. GIF uses a loss-less compression algorithm based on LZW. LZW is patented in some countries. A new standard, PNG, uses similar, non-patented compression algorithm and supports a wider range of image types including full colour images. PNG is well supported in recent software.
- A Graphical User Interface (GUI) is a computer interface which consists of visual controls such as menus, buttons and windows. The alternative to a GUI is a console or command-line interface, where the user must type commands as text rather than using visual controls such as menus and buttons. A GUI is widely regarded as easier to use, but it is much more complicated to create.