Derrida brings to a text the knowledge that the marks on a page are not random markings, but signs. A sign has a dual aspect as signifier and signified, signal and concept, or mark-with-meaning. To account for significance, Derrida turns to a highly specialized and elaborate use of Saussure's notion that the identity either of the sound or of the signification of a sign does not consist in a positive attribute, but in a negative (or relational) attribute-that is, its "difference" or differentiality, from other sounds and other significations within a particular linguistic system. This notion of difference is readily available to Derrida, because inspection of the printed pages shows that some marks and sets of mark repeat each other, but that others differ from each other. In Derrida's theory 'difference' itself supplements the static element of a text and it can be taken as to mean 'negativity'. 'Difference puts into motion the incessant play of signification that goes on within the seeming immobility of the marks on the printed page.
Derrida calls what is distinctive in the signification of a sign "trace". This means what "appears" or "disappears".