Structure of Language: Conceptual framework, notation & semantics
Conceptual framework is a (mental) structure that acts as a schema of representation. It gives us a means to focus, structure and organise perceptions of the world.
Notation is a system of signs/symbols that includes rules for the arrangement of the signs or symbols. It specifies how models are represented.
Semantics is some form of correspondence between a surrogate and its intended (or actualised) referent in the world. It specifies the rules of how models are interpreted (human knowledge or computational rules).