This Mac comes pre-installed with OS X Snow Leopard, but you can order a free upgrade to OS X Lion via Apple's OS X Lion Up-To-Date program for a limited time (depending on the date of your purchase).
It also comes with the Mac OS X Snow Leopard operating system as well as the iLife software suite, which includes the latest versions of iPhoto, iMovie, and GarageBand. Other features include integrated Wireless-N Wi-Fi networking, Bluetooth connectivity, an SD card slot (compatible with SDHC and SDXC cards), one Thunderbolt port, a FireWire 800 port, and a total of four USB 2.0 ports (see full specifications below). This 21.5-inch model (MC309LL/A) offers improved graphics with AMD Radeon HD 6750M discrete graphics featuring 512 MB of GDDR5 memory, a 500 GB hard drive, and 4 GB of installed RAM. The iMac's display offers a 1920 x 1080-pixel resolution (for native 1080p high-definition viewing), and it uses IPS technology to deliver consistent color across an ultra wide 178 degree viewing angle. Now more powerful, more advanced, and even more incredible than before. All from a beautiful, widescreen 21.5-inch LED-backlit display that takes up just a sliver of your desk. And a new FaceTime HD camera lets you make full-screen HD video calls. It also brings Thunderbolt I/O technology to the desktop for lightning-fast data transfer. The new iMac features next-generation Intel Core i5 quad-core processors and the fastest graphics ever in an all-in-one computer. The 21.5-inch iMac features a brilliant LED-backlit, edge-to-edge glass display (see larger image).