Skeuomorphism refers to a design principle in which design cues are taken from the physical world. This term is most frequently applied to user interfaces (UIs), where much of the design has traditionally aimed to recall the real world - such as the use of folder and files images for computer filing systems, or a letter symbol for email - probably to make computers feel more familiar to users. However, this approach is increasingly being criticized for its failure to pioneer designs that truly harness a computer's superior capabilities, rather than forcing it to merely mimic the behavior of a physical object.
The term skeuomorphism is derived from the Greek words "skeuos," which means vessel or tool, and "morphe," which means "shape."
Skeuomorphs are deliberately employed to make the new look comfortably old and familiar, or are simply habits too deeply ingrained to wash away.
Many computer programs have a skeuomorphic graphical user interface that emulates the aesthetics of physical objects. A more extreme example is found in many audio processing software packages, which closely emulate physical musical instruments and audio equipment. Functional input controls like knobs, buttons, switches, and sliders are often careful duplicates of those found on the original physical device being emulated. Some software even includes graphical elements of the original design that serve no user interface function, such as handles, screws, and ventilation holes.
Even systems that do not diplay images of some physical object frequently contain skeuomorphic elements, such as slider bars that emulate linear potentiometers and tabs that behave like tabbed file folders. Skeuomorphs need not be visual. The shutter-click sound emitted by most camera phones when taking a picture is an auditory skeuomorph: it does not come from a mechanical shutter, which camera phones lack, but from a sound file in the phone's operating system. Another example is the swiping hand gesture for turning the "pages" or screens of a tablet.