R/E : Reduction & Enlargement, some machines may also have a zoom lens in which the image size can be altered in 1% increments. DF, ADF, RADF : Document Feeders automatically load the original(s) to be copied onto the copyboard glass. The Document Feeder feeds only a single original at a time. The Auto Document Feeder will feed a stack of 20 to 50 originals automatically to the copyboard glass for copying. The Reversing Automatic Document.
Feeder has basically the same function as the ADF except it has the ability to handle two sided originals. This feature will recirculate and flip over the originals allowing it to copy the second/back side of the original. SORTER : This collating feature will allow you to make multiple copies of multiple originals, e.g., the ability to make books and manuscripts. The number of sorter bins/trays vary between 10 to 40, the most common a 20 bin sorter.
Misc. Features : Some of the other features may include Duplexing (automatic two sided copying), Image Editing, special Book Copying Mode, and multiple colors.