Source : Free On-Line Dictionary of Computing

back quote
     
         "`" {ASCII} code 96.  Common names: left quote;
        left single quote; open quote; {ITU-T}: grave accent; grave.
        Rare: backprime; {INTERCAL}: backspark; unapostrophe; birk;
        blugle; back tick; back glitch; push; {ITU-T}: opening single
        quotation mark; quasiquote.
     
        Back quote is used in {Unix} shells to invoke {command
        substitution}.
     
        (1996-11-26)