Apple is cashing in on the popularity of its iPhone and iPad to boost demand for its oldest product, the Macintosh.
The company launched a revamped MacBook Air at an event dubbed "Back to the Mac" at its Cupertino headquarters.
The computer is seen as a marriage of what Apple has learned from desktop computing and mobile devices. Like the iPad, the Air will have no hard drive and rely on flash memory.
"It's like nothing we've ever created before," said Apple boss Steve Jobs.
"We see these as the next generation of MacBooks. We think all notebooks are going to be like this one day. We've been inspired by some of the work we have done on iOS and want to bring them back to the Mac," said Mr Jobs.
Analysts said the new product sends out a clear signal to the industry.
"This is a strong reminder to everyone out there that Apple is still in the PC business," said Michael Gartenberg, research director with Gartner.
"They are still making a lot of money in the PC business and if anyone thinks they are getting out of that business given the money they are making they are very mistaken."
The new MacBook Air is 0.11 inches thick at its thinnest point. Apple said the computer's battery life lets users surf the web for seven hours. In standby mode, the battery can last 30 days.
Models start at $999 and are now shipping.
The first Macintosh The first Macintosh made its debut on 24 January 1984
In an overview, Apple said the Macintosh accounted for a third of the company's revenue or $22bn in the fiscal year that has just ended.
They sold 13.7 million Macs last year, which is three times the sales they had in 2005. The firm also cited research figures that showed Apple now controls 20.7% of the US consumer market and accounts for one in every five computers sold.
"The Mac company, if it were a standalone company, and we have no plans to do that, would be 110 on the Fortune 500 list," said Tim Cook, Apple's chief technology officer.
Apple also unveiled a new version of the Macintosh operating system, called Lion, to be released next summer.
The new OS is designed to take advantage of some of the features of the mobile iOS by bringing them to the desktop.
"Lion brings many of the best ideas from the iPad back to the Mac, plus some fresh new ones," said Mr Jobs.
The company revealed that Macs will soon have an application store mirroring the one that exists for the iPhone and the iPad.
A launchpad will make it easy to organise and launch apps in the new version of the operating system.
The store will open in 90 days.
FaceTime, which debuted on the iPhone 4 this summer, will bring video-chatting to Macs.
Also being updated is Apple's flagship software suite iLife. The new edition includes updates to iPhotos, iMovie, GarageBand, iDVD and iWeb.
With the refreshed iPhoto feature, it will be easier for users to email photos and turn pictures into books and cards.