A grammar rule contains two categories of rules: syntax rules and semantic rules.
Syntax rules define the structure of a language, including the order in which words can be arranged to form sentences and the grammatical relationships between words. Syntax rules ensure that sentences are constructed in a way that is grammatically correct and makes sense.
Semantic rules, on the other hand, define the meaning of words and sentences. Semantic rules ensure that the meaning of the sentence is conveyed accurately and appropriately, taking into account the context and intended message.
Together, syntax and semantic rules help to ensure that language is used in a clear, consistent, and meaningful way.