Saussure introduces his theory of the linguistic sign, which is composed of the signifier (the sound pattern) and the signified (the concept or meaning). He argues that the relationship between the signifier and signified is arbitrary - there is no natural connection between the sound of a word and its meaning. For example, the sounds "s-o-r" in French arbitrarily signify the concept of sister. Saussure also notes that the linguistic sign is linear, as the sound signal occurs over time rather than space. His work established modern linguistic analysis and the understanding of language as a system of interconnected signs.