Introduction -- Hereditary Classes of Graphs -- What Word-Representable Graphs Are and Where They Come From -- Characterization of Word-Representable Graphs in Terms of Semi-transitive Orientations -- Various Results on Word-Representable Graphs -- Open Problems and Further Research Directions on Word-Representable Graphs -- Interrelations Between Words and Graphs in the Literature -- More on Interrelations Between Words and Graphs in the Literature -- App. A: Graph Theory Background -- App. B: Beyond Graph Theory Background.