User`s guide

Frequently used in opposition to the term fixed-spacing,
proportionally-spacing places the characters according to their
individual sizes, and can increase legibility and readability. All of
your printer’s typefaces except Courier are proportionally spaced
typefaces.
Character Set A character set is a collection of symbols. The
symbols contained in character sets are designed to perform various
printing applications. Many sets are composed of the alphabet, the
numbers zero through nine, and an assortment of other symbols,
such as the dollar sign and the ampersand.
Family A typeface family is a group of similar typefaces. For
example, the Times-Roman typeface family has four members:
Times Roman, Times Bold, Times Italic, and Times Bold Italic
Chapter 5
5-8 Professional Printing