The term ‘proposition’ has multiple uses both within linguistics and outside. A proposition is, at any rate, a semantic entity. Some related concepts like ‘clause’ and ‘sentence’ are not of purely semantic entities, but of significative linguistic units whose meaning may be a proposition. But even inside the domain of such objects which are the meaning of a sentence or clause, the proposition must be delimited against concepts like ‘state of affairs’ and ‘utterance’. These are the topics of the present section. The last subsection visualizes the position of the proposition in a layered structure.