all-in-one - Computer Definition
(1) A combination printer, scanner, copy machine and fax machine. Some all-in-ones exclude the fax capability or make it an option.
(2) 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.