ASCII is the original name of the standardized character code used up until the advent of unicode. It stands for "American Standard Code for Information Interchange", which has become an anachronism. By 1977, the title on the standards document was "American National Standard for Information Interchange" (ANSI X3.4-1977) and usage has become more and more international since then. It does, however, survive in English-speaking regions and has pride of place as the first 127 code points in the unicode standard since it was the first publicly standardized code.
ASCII was inherently a 7-bit code at least until X3.64-1979, perhaps because at the time it was created it was still sensible to reserve the 8th bit on the paper tapes commonly in use, as a parity bit to guard against data corruption.
- American National Standards Institute (ansi.org)