multifunction machine; MFP
General term for a device that combines multiple functions, such as printing, copying, scanning, and faxing.
新しい複合機をオフィスに導入した。
We introduced a new multifunction machine in the office.
all-in-one printer; combination printer-copier-scanner-fax
Specifically refers to an office machine that integrates printing, copying, scanning, and fax capabilities.
この複合機はプリント、コピー、スキャン、ファックスが一台でできる。
This all-in-one printer can print, copy, scan, and fax in one unit.
複合 (compound, composite) + 機 (machine). A straightforward modern compound.