The key to understanding Saussure is to view the linguistic sign a process rather than a thing. It is a mental relationship between a sound pattern (Signal) and a concept (Signification). Other literature would say Signifier and Significant - but in keeping to this literature we will stick with Signal and Signification. To Saussure, the "linguistic sign is not a link between a thing and a name, but between a concept and a sound pattern. The sound pattern is not actually a sound; for a sound is something physical. A sound pattern is the hearer's psychological impression of a sound." It is the link between the signal and the signification that comprises the sign. It is not just a relation, but a relation from an abstract entity to an abstact entity. It is easier to understand the abstraction if you take into account that the signal and the signification to be processes rather than things.