The Full Form of GFX is‍ Graphics.

Graphics (from Greek γραφικός graphikos, “belonging to drawing”) are visual images or designs on some surface, such as a wall, canvas, screen, paper, or stone to inform, illustrate, or entertain. In contemporary usage, it includes a pictorial representation of data, as in c manufacture, in typesetting and the graphic arts, and in educational and recreational software. Images that are generated by a computer are called computer graphics.