The general facsimile sends and receives paper documents. In contrast, the PC-Fax TX function sends a document data on a Windows PC as if it was printed on this machine.
This is well suited for an environment where you handle a large number of data files because it is not necessary to prepare paper documents to send faxes.
The fax destinations can be set using the Address Book already stored on this machine. Also, you can create a phone book and control the destinations on the PC.