Signified and signifier

In semiotics, signified and signifier (French: signifié and signifiant) are the two main components of a sign, where signified is what the sign represents or refers to, known as the "plane of content", and signifier which is the "plane of expression" or the observable aspects of the sign itself. The idea was first proposed in the work of Swiss linguist Ferdinand de Saussure, one of the two founders of semiotics.