“…We start in §2 with the axiomatic definition of vertex algebra, which is somewhat different from, but equivalent to Borcherds' 875-02 original definition (see [DL,FKRW,K2]). We then discuss some of their most important properties and give the first examples, which come from infinite-dimensional Lie algebras, such as Heisenberg, affine Kac-Moody and the Virasoro algebra.…”