SAN FRANCISCO — Apple is throwing out most of the real-world graphical cues from its iPhone and iPad software in what it calls the biggest update since the iPhone's launch in 2007.
The new operating system, called iOS 7, strives for a clean, simple, translucent impression. Apple is redesigning all its applications and icons to conform to the new look, driven by long-time hardware design chief Jony Ive.
Apple demonstrated the new software at the Worldwide Developers Conference in San Francisco on Monday. The new design direction was widely expected and will show up on iPhones, iPad and iPod Touches this fall, the company said.
The software uses simple graphical elements in neon and pastel colors. Gone is the effort to make the icons looks like three-dimensional, embossed objects, including throwing out the casino-green "felt" of its Game Center app.
Interface designers call the new guiding principle "flat," but on the iPhone's main screen, the background image will move subtly with the movement of the device, creating an illusion of depth. Other screens include plenty of white space.
While design modifications could help Apple distinguish its devices from rival phones and tablets, the company risks alienating longtime users.
Raluca Budiu, a senior researcher specializing in usability at the Nielsen Norman Group, said the "flat" design can confuse users, because it can offer fewer signals about where to tap or click. That has been the case, she said, with Windows 8, which has a very flat design. Budiu said it's too early to say if it will be an issue with iOS.
Budiu noted that iOS users seem quite happy with the current iOS, which is easier to use than Google Android, its only big competitor.
Apple made a rare, major stumble with last year's iOS update, when it replaced Google's Maps application with its own navigation app. The underlying data for Apple's Maps was spottier and less accurate than Google's, users found. But the Maps fracas didn't diminish the demand for iPhones.
Among other changes, Apple's new iOS system will update apps automatically. It will store Web passwords online in Apple's synching service, iCloud, making them available across devices. The AirDrop feature will allow sharing of big files with Apple-equipped people in the same room.
Apple took a jab at its rival, Samsung Electronics Co., which had been touting its Galaxy phones as better than iPhones because they sport near-field communication chips that allow people to share files by bumping phones together.
Apple is also launching a Pandora-like Internet radio service, iTunes Radio. It will be built into the Music app and stream music for free. There will be advertising, except for people who pay $25 a year for the iTunes Match online music storage.