A backslash (\) is a symbol or typographical mark used in computer and computing applications to perform specific operations and tasks. It is part of the ASCII characters set and is mainly used in computer programming and operating system commands.
Backslash is also known as reverse slash, slosh, backslant, backslat, backwhack, bash, escape, hack, reverse slant, reversed virgule and reverse solidus.
Techopedia explains Backslash
Backslash was initially introduced by Bob Bemer in ASCII to represent the Boolean operators AND as "/\" and OR as "\/". In programming languages, it has various different uses. In C and Perl programming languages, for example, it is used as an escape character, to introduce special characters within Haskell and as a line delimiter in general. In operating systems, backslash is used to define and separate folders and directories when writing/passing commands.