Associated Press

Apple is throwing out most of the real-world graphical cues from its iPhone and iPad software, such as the casino-green "felt" of its Game Center app, 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 look. Apple is redesigning all its applications and icons to conform to the new look.

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 strives for a multi-layered look, with translucent panels. On the main screen, the background image moves subtly with the movement of the phone, creating an illusion of depth. Other screens are padded out with plenty of white space.

The software has "a whole new structure that is coherent and is applied across the entire system," Ive said in a recorded presentation. "The design recedes, and in doing so, elevates your content."

While design modifications could help Apple distinguish its devices from rival phones and tablets, they risk alienating longtime users.

Among other changes, Apple's new iOS system will update apps automatically. It will store Web passwords online in Apple's syncing service, iCloud, making them available across devices. The AirDrop feature will allow sharing of big files with Apple-equipped people in the same room.

The company also stepped up its rivalry with Google, maker of the Android software on Samsung and other phones. Apple said the Siri virtual assistant will use searches from Microsoft's Bing, Google's rival. Apple also is bringing its mapping service to desktops and laptops to compete with Google Maps and others.

The Cupertino, Calif., company 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 per year for the iTunes Match online music storage.

Apple was a pioneer of online music sales and is still a leader in that field, but streaming services such as Pandora and Spotify have emerged as popular alternatives to buying.

Apple updates its iOS operating system every year and doesn't charge for the updates. The new operating system will be available for the iPhone 4 and later models, and on the iPad 2 and later models, including the Mini.

Also at the conference, which runs through Friday, Apple revealed it's switching from its more than decade-long practice of naming its Mac operating system updates after big cats. Instead, it's paying homage to the geography of its home state. Federighi says the next version of Mac OS X will be called Mavericks, after an undersea rock formation that produces big waves near Half Moon Bay, Calif.