It Used to be said that multifunction printer was jack of all trades but a master of none .That’s no longer the case .
You can get good quality prints and scans from a multifunction unit.additionally , both operations usually work better togther in one machine than if you bought a printer and a scanner separately.
You can copy a document directly from a scanner to a Printer, for example ,without having to route the image through your computer .Multifunction printers come in two varieties :

Office Oriented models have an automatic document reader for scanning multiple pages as a single task, and often include a built in fax machine .

Photo Oriented models let you scan slides and negatives , and usually have built in media slots for importing images directly from digital camera memory cards .
Multifunction laser Printers designed for office use can replace a small Workgroup’s printer , copier and fax machine.