Resolution; Sides Scanned - Xerox Document Centre 240 Reference Manual

Resolution

The resolution affects the appearance of the fax at the receiving fax
terminal. A higher resolution yields better quality for photos. A
lower resolution reduces communication time.
Standard (200 x 100 dpi) - Is recommended for text documents. It
requires less communication time, but does not produce the best
image quality for graphics and photos.
Fine (200 x 200 dpi) - Is recommended for line art. It produces
output with a resolution between super fine and standard. This is the
default resolution and the best choice in most cases.

Sides Scanned

This selection allows you to scan 1-sided, 2-sided or 2-sided rotated
originals:
1 Sided -each original is single-sided.
2 Sided -each original is double-sided.
2 Sided Rotate - This is ideal if your second side is in a head to toe
configuration.
Xerox Document Centre Reference Guide Page 5 - 11