4K iMac
Apple's iMacs now come in two higher-resolution display options: a 21.5-inch 4K model and a 27-inch 5K model. Apple Inc.

Apple upgraded its line of iMac desktop computers Tuesday, bringing higher resolution displays and faster processors. Among the upgrades to the 21.5-inch iMac is 4K resolution, or 4096x2304 pixels -- about four times as many pixels as 1080p.

The change comes one month after Apple introduced its iPhone 6S and 6S Plus, which come with a 12-megapixel camera that supports video recording in 4K resolution. Apple also dropped its non-Retina 27-inch iMacs and replaced them entirely with 5K resolution display models, which have seven times as many pixels as a standard HD screen. The 27-inch line features AMD Radeon R9 graphics and Intel’s sixth-generation Core processors, also known by the code name Skylake. The 21.5-inch 4K iMacs come with Intel’s fifth-generation Broadwell chips and Iris Pro graphics. All iMacs now come with two Thunderbolt 2 ports to use with external displays and compatible accessories and 802.11ac Wi-Fi for wireless networking speeds up to 1.3Gbps.

The 4K 21.5-inch iMac starts at $1,499, and Apple’s 27-inch models start at $1,799. Those looking for a cheaper iMac can still purchase a regular display 21.5-inch model, starting at $1099.

In addition to the new iMacs, Apple also unveiled three redesigned wireless accessories, dubbed the Magic Keyboard, Magic Mouse 2 and Magic Trackpad 2. Each device features rechargeable batteries that eliminate the need for rechargeable batteries, as were used in the previous models. Apple claims that the rechargeable batteries of each accessory should last about a month before a recharge is needed through a lightning cable.

The Magic Trackpad 2 also brings the pressure-sensitive Force Touch technology to Apple’s desktop computers, enabling users to access new gestures and controls in OS X and apps, as described on their support page. The Magic Keyboard is available for $99, the Magic Mouse 2 for $79 and the Magic Trackpad 2 retails for $129.