The structure of strings in some language. A language's syntax is described by a grammar. For example, the syntax of a binary number could be expressed as

        binary_number = bit [ binary_number ]
        bit = "0" | "1"

meaning that a binary number is a bit optionally followed by a binary number and a bit is a literal zero or one digit.

The meaning of the language is given by its semantics.

See also abstract syntax, concrete syntax.