Back quote
Alternatively referred to as an acute, grave, grave accent, left quote, open quote, or a push, the back quote or backquote is a punctuation mark (`) found on the same U.S. computer keyboard key as the tilde. Below is an example of a Perl syntax that uses back quotes to execute a system command and loads it into the files array.
@files = `dir /b c:\windows\temp`;
Although not as common as the above alternative meanings, this mark is also sometimes referred to as a back glitch, back prime, back spark, back tick, birk, blugle, quasiquote, and unapostrophe.
Also see: Quote, Keyboard definitions, Single quote