This lecture by Clémentine Lemarié-Rieusset introduces the quadratic linking degree, a concept in motivic knot theory that serves as an algebraic geometry counterpart to the linking number in knot theory. The lecture covers knot theory basics, oriented links in algebraic geometry, homotopies, Chow groups, intersection theory, Chow-Witt groups, Milnor-Witt K-theory, and quadratic forms. The quadratic linking degree is defined through Seifert classes, homotopies, and intersection products, with examples like the Hopf link and the Solomon link being discussed. The lecture concludes with a presentation of the preprint 'The Quadratic Linking Degree' by Clémentine Lemarié-Rieusset.