Which term refers to the grammatical rules of a programming language?

The term that refers to the grammatical rules of a programming language is syntax. Syntax defines the specific structure and format that code must adhere to in order to be correctly interpreted by a compiler or interpreter. It dictates how the various elements of a programming language should be arranged—such as keywords, operators, and punctuation—so that the code can be executed without errors.

For instance, in many programming languages, the use of parentheses to group expressions or the requirement for semicolons to terminate statements are part of the syntax rules. If these rules are not followed, the code will not compile or run correctly, highlighting the importance of understanding syntax in programming.

Other important concepts related to programming languages include semantics, which refers to the meaning of the constructs within the programming language, and lexicon, which is more about the vocabulary used in a language. Grammar, while it can be a broader term encompassing both syntax and semantics in natural languages, is less specific in the context of programming languages than syntax is.