We use the term semantics to refer to the mapping between (tangible) terms and (intangible) concepts (their meaning, the ideas behind it). Semantics are scoped, i.e. every scope has its own semantic mapping. This implies that every party has - and maintains - its own (subjective) semantics, which is its subjective mapping of a set of terms onto the concepts/ideas in its knowledge. The (erroneous) assumption that parties would (automagically) share a semantics is the cause of many misunderstandings, and hence should be identified and deleted as soon as possible.
The ability to distinguish between (non)semantics helps us to better understand one another, because it makes one aware of the fact that semantics is subjective, and its owner can update it. This allows such an owner to (temporarily) use terms in the same meaning as another party, specifically if they agree to use good definitions.