The set of rules that defines the combination of symbols that are considered to be correctly structured statements or expressions in that language is called...

The set of rules that defines the combination of symbols that are considered to be correctly structured statements or expressions in a language is called Syntax. Think of syntax as the grammar of a language. Just like in English, there are certain rules that dictate what combinations of words and punctuation are considered to be a proper sentence, in programming languages there are rules that dictate what combinations of symbols and syntax are considered to be a proper statement or expression. The syntax of a language determines how code should be written in order for it to be properly understood by the computer and executed as intended.