Jakobson was one of the most influential intellectuals of the 20th century, with his contributions to linguistics, structuralist anthropology (he was an inspiration to Claude Levi-Strauss), literary theory and semiotics, among others.
Jakobson's three major ideas in linguistics play a major role in the field to this day: linguistic typology, markedness and linguistic universals. The three concepts are tightly intertwined: typology is the classification of languages in terms of shared grammatical features (as opposed to shared origin), markedness is (very roughly) a study of how certain forms of grammatical organization are more "natural" than others, and linguistic universals is the study of the general features of languages in the world.