iMac (21.5-inch, Late 2013)

The iMac is a series of all-in-one computers from Apple, sold as part of the company's Mac family of computers. First introduced in 1998, it has remained a primary part of Apple's consumer desktop offerings since and evolved through seven distinct forms. The iMac natively runs the macOS operating system.

Its original form, the iMac G3, had a gumdrop, egg-shaped look with a CRT monitor, mainly enclosed by a colored, translucent plastic case. The computer was, at the time, an inexpensive, consumer-oriented computer that would easily connect to the Internet. The second major revision, the iMac G4, moved a design with a hemispherical base containing all the main components and an LCD monitor on a freely moving arm attached to it. The third and fourth revisions, the iMac G5 and the Intel iMac, placed all the components immediately behind the display in a plastic casing, creating a slim unified design that tilts only up and down on a simple metal base. The fifth, sixth and seventh revisions swapped the plastic enclosure for metal and became progressively thinner over each revision.