While the familiar aluminum design remains, the new iMac is much thinner than its predecessor. The company reengineered the iMac's internals and display, and Apple says the display system is 45 percent thinner and 8 pounds lighter.

The new iMacs are available in 21.5- and 27-inch models, with displays that support native resolutions of 1920-by-1080 pixels and 2560-by-1440 pixels, respectively. Previous models of the iMacs had a 2mm air gap between the glass and the display; that gap has been removed in the new iMac. Apple now laminates the display directly to the glass, and the company says the full lamination will improve optical quality.

Besides the new design, the other marquee feature of the new iMac is the , which is a hybrid storage technology that combines flash storage with a hard drive. The Fusion Drive comes with 128GB of flash storage used mainly by the operating system to provide fast performance. The hard drive portion of the Fusion Drive is available in 1TB or 3TB capacities.

However, the Fusion Drive isn't part of Apple's standard configuration for the iMac--it is a build-to-order option. Apple has yet to release upgrade pricing for the iMac models with a Fusion Drive, though it's worth noting that the 1TB Fusion Drive upgrade for the 2.3GHz Core i7 Mac mini is $250.

As seen with the , Apple is relying on Thunderbolt and USB 3.0 for connectivity. The iMac has two Thunderbolt ports and four USB 3.0 ports, as well as a gigabit ethernet port. FireWire is no longer offered on the iMac, and users of FireWire devices will need to use an adapter.