backticks

Backticks, also known as grave accents, are the character ` (ASCII/Unicode U+0060). They are distinct from the apostrophe ’ or ’ in most fonts and should not be confused with single quotes.

In typography, the grave accent is a diacritic placed over certain letters in various languages to indicate vowel quality or stress; it is separate from the backtick character and is usually printed as diacritic marks on letters (à, è, ì, ò, ù, etc.). The backtick itself is rarely used for diacritic purposes in modern digital text.

In computing, backticks appear in several contexts. In Unix-like shells, they historically enclose a command for substitution, capturing its output into another command or variable. Modern shells tend to favor the $(command) syntax, but the older form remains supported for compatibility. In Windows PowerShell, the backtick serves as an escape character to introduce special sequences.

In programming languages, backticks take different forms. JavaScript uses backticks to declare template literals, enabling string interpolation and multi-line strings. In R, backticks can quote non-syntactic identifiers such as names with spaces. In SQL, backticks are used by MySQL and some forks to delimit identifiers like table or column names, allowing reserved words or unusual characters; standard SQL typically uses double quotes instead.

In markup and documentation, backticks are used to denote code. In Markdown, for example, inline code is wrapped in single backticks and code blocks in triple backticks; other formats vary.