"In the physical world, a skeuomorph is an ornamental version of something that was, in an earlier product, a functional necessity. Fake shutter sounds in digital cameras. Fake candles in electric chandeliers. Fake grain in leatherette."
"(In software) Those shapes don’t serve any technological function. But there is, of course, a human reason for software skeuomorphs. In the 1980s, to help the public make the transition to computers, Apple and Microsoft designers chose real-world shapes for on-screen icons to convey their meanings."
"These design features, critics argue, no longer help novices make a transition. You don’t need unsightly paper remnants to understand that you are using a calendar."
"Skeuomorphism in software has its place when used well: it can put you at ease with a new program in a flash and convey functions with simple visual metaphors (camera apps will always have camera icons). As with any design concept, this one can be taken too far. The instant a skeuomorph makes software less pleasant to use, somebody should rein it in."
From “Apple Shouldn’t Make Software Look Like Real Objects”, Scientific American