The new iMac features an ultra slim design and will be available in two models, a 27-inch iMac with a 2560 x 1440 resolution and a 21.5-inch display with 1920 x 1080 resolution.
It will feature an Intel Core i5 or i7 processor, 8GB of RAM, up to 3TB of memory, two thunderbolt ports and four USB 3.0 ports.
The new iMac will also implement Apple's new fusion drive, which combines a 128GB solid state drive with a standard hard drive. The iMac will automatically store the most used files and programmes on the solid state drive, allowing for quicker access to those applications.
Apple also revealed an update to its Mac mini line of computers to bring them up to Intel's Core i5 and i7 processors.
The new Mac minis will have the same compact aluminium case as the previous model, expanded with four USB 3.0 ports and 4GB of RAM in addition to the standard Thunderbolt, HDMI, SD card, Ethernet and FireWire 800 ports.
The 21.5-inch iMac will ship in November starting at $1,299 (£1,099) with a 2.7GHz Intel Core i5 processor and NVIDIA GeForce GT 640M graphics card.
The 27-inch iMac arrives a month later in December starting at $1,799 (£1,499) with a 2.9GHz Intel Core i5 processor and NVIDIA GeForce GTX 660M graphics card.
The Mac mini begins shipping today with a 2.5GHz Intel Core i5 processor and 500GB hard drive for $599 (£499). A $999 (£849) server version is also available starting today, featuring a 2.3GHz quad-core Intel Core i7 processor and two 1TB hard drives.
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