A combination printer, scanner, copy machine and fax machine. Some all-in-ones exclude the fax capability or make it an option.
A desktop computer that houses every component except the keyboard and mouse inside the same case as the monitor. Its primary advantage is saving space. Its disadvantages are twofold: if any component fails, the entire unit must be brought into the shop for repair. Secondly, there is generally no internal room for adding another drive. See mini PC
An iMac All-In-One
With the computer inside the monitor, iMacs have been very popular since their introduction in 1998. This is a 2009 model (see iMac
). (Image courtesy of Apple Inc.)