ASCII is a character set standard in which each byte represents one character.
The Teradata translation codes for the ASCII client character set are permanently enabled in Database Engine 20.
Industrial, national, and international organizations have developed custom character sets that are extensions of the ASCII standard. If you use accented and non-Latin characters, do not use the ASCII client character set. UTF8 is an extension of ASCII that includes all characters generally used in character-based information.
For characters outside the standard 7-bit ASCII range, use a Unicode session character set (UTF8 or UTF16) and an appropriate server character set.