GUI

Graphical user interface.

Well known examples of software with a GUI would be Photoshop or the GIMP, Firefox, and Inkscape. Programs like the GIMP, Firefox, Inkscape, though their primary interface is graphical, may also offer certain functionality via the command line. Try running them from the shell with a "--help" option, or view their man pages to find out more.

See Wikipedia:Graphical User Interface

Contrast with Command-line Interface.