All-in-One PC

The original iMac, an example of a modern-day AIO. Unlike many previous AIOs, the iMac featured built-in speakers and a unique "egg-shaped" case.

An All-in-One computer (or AIO) is a personal computer that combines the tower case of the computer with the monitor to create a single unit. Many of the early personal computers from the late 1970's to the late 1980's, such as the Atari 800 and Commodore 64, were AIOs. Recently, the form factor was re-popularized by Apple, Inc.'s iMac, which was first released in 1998.

AIOs share many design considerations with laptops. Because of the limited amount of space in an AIO's case, they often can not accommodate a hotter processor. Apple's iMac, for instance, uses a laptop CPU. Additionally, they tend to offer fewer expandibility options, such as extra internal hard drive bays or expansion slots, due to size limitations.