Skeuomorphism

What is Skeuomorphism?
Skeuomorphism refers to a design principle in which design elements come from the physical world. This term is most commonly applied to user interfaces (UIs), where much of the design has traditionally been aimed at reminding the real world - such as the use of folder and file images for computer filing systems or a letter icon for email on computers feel more familiar to users.
However, this approach is increasingly criticized for its lack of ingenuity and its inability to come up with designs that truly harness the superior capabilities of a computer, rather than merely forcing it to 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 “form”.

Skeuomorphism is known to be one of Apple's key design principles and part of its Human Interface Guidelines. However, the shape of Apple partners' skeuomorphism is largely a subtle shape that suggests something real, but doesn't necessarily seek to replicate it. However, in 2011 Apple came under fire when some of its iOS applications took on decidedly country western style.
Overall, skeuomorphism came under increasing attack, mainly because many of the nostalgic elements it tries to depict - such as calendars, daily planners, address books, etc. - are almost entirely alien to the younger generation of users. Critics of skeuomorphism also point out that physical objects in design are an obstacle to the development of useful designs.

For example, many digital calendars look and behave similarly to a normal paper wall calendar; Leaving this structure could make it much more intuitive to users. In other words, design can be constrained by tying it to physical objects, even though computers are not subject to those constraints.