The Free On-line Dictionary of Computing (30 December 2018):
"'" ASCII character 39.
Common names include single quote; quote; ITU-T: apostrophe.
Rare: prime; glitch; tick; irk; pop; INTERCAL: spark;
ITU-T: closing single quotation mark; ITU-T: acute accent.
Single quote is used in C and derived languages to introduce
a single character literal value which is represented
internally by its ASCII code. In the Unixshells and
Perl single quote is used to delimit strings in which
variable substitution is not performed (in contrast to
Single quote is often used in text for both open and close
single quotation mark and apostrophe. Typesetters use two
different symbols - open has a tail going up, close and
apostrophe have tails hanging down (like a raised comma).
Some people use back quote (`) for open single quotation