Let's take a minute to go back over the character-encoding terms from Chapter 2:
An abstract character repertoire is a collection of characters.
A coded character set maps the characters in an abstract character repertoire to abstract numeric values or positions in a table. These abstract numeric values are called code points. (For a while, the Unicode 2.0 standard referred to code points as “Unicode scalar values.”)
A character encoding form maps code points to series of fixed-length bit patterns known as code units. (For a while, the Unicode 2.0 standard referred to code units as “code points.”)