In 2007 Apple redesigned the iMac and moved from an entire plastic housing unit to a duel plastic and machined aluminium design. The rear housing of the machine would be made of plastic whereas the front bezel was aluminium. The first models to adopt this design were the 20” and 24” iMacs who’s run lasted until October 2009 when Apple would release the 21.5” and 27” form factor machines. Although a 20” model would remain as a part of Apples education store. The 2009 redesign seen Apple moved away from any form of plastic housing to a full aluminium enclosure. The 21.5” and 27” ranges would receive their only redesign in 2012 which featured a slimmer body with an edge to edge display, the 21.5” would see its last update in 2019 before being discontinued in April 2021 where as the 27” model would see its last update in 2020 before being discontinued in March 2022 thus bringing an end officially to both the 21.5” and 27” iMac models.
In 2021 Apple announced a completely new iMac whilst reviving the 24” form factor and drew inspiration from the original iMac G3 machines. Apple would release the first iMac to feature their own SoC and they were the first iMacs since the G3 that were available in multiple colours, marking yet another milestone in the life of the iMac.