A fax kit (also known as a fax board) is an accessory that adds a faxing feature to a multifunction printer/scanner/copier (MFP).
While fax boards are another name for fax kits, the term “fax board” typically applies to both MFPs as well as servers, while the term “fax kit” typically applies only to MFPs.
Most MFPs have scan and fax as options. The fax kit (as well as scan options) can be added at the time of purchase or at a later date to enable faxing features.
Often MFPs with a fax kit can have some advanced fax features, such as forwarding a fax to email as well as auto-resending a fax if it reaches a busy signal.