In brief, a graphical user interface can be defined as follows. A user interface, as recently described, is a collection of techniques and mechanisms to interact with something. In a graphical interface, the primary interaction mechanism is a pointing device of some kind.
What the user interacts with is a collection of elements referred to as objects. They can be seen, heard, touched, or otherwise perceived. Objects are always visible to the user and are used to perform tasks. They are interacted with as entities independent of all other objects.
People perform operations, called actions, on objects. The operations include accessing and modifying objects by pointing, selecting, and manipulating.
Popularity of Graphics
Graphics revolutionized design and the user interface. Graphics assumes three dimensional look whereas text based system assumes one dimensional look.
Information can appear or disappear through floating windows and navigation and commands can be done through menu or pull downs or screen controls
Increased computer power and the vast improvement in the display enable the userâ€™s actions to be reacted to quickly, dynamically, and meaningfully.
If properly used graphics can reduce mental and perceptional load and increases information transfer between men and machine because of visual comparisons and simplification of the perception of structure.