Subfactors and vertex operator algebras are mathematical structures that at first glance appear very different, but both are used in the mathematical study of quantum field theory. In particular, vertex operator algebras are algebraic structures arising in two-dimensional conformal field theory (CFT), a quantum field theory with applications ranging from string theory to condensed matter physics to quantum computing. On the other hand, subfactors are closely related to conformal nets, which are a functional-analytic approach to CFT. Because they are both mathematical descriptions the same quantum field theory, the theories of vertex operator algebras and conformal nets are widely believed to be equivalent, but only in the last few years has there been substantial progress in establishing an equivalence. As many important results in conformal field theory have been established for either vertex operator algebras or conformal nets, but not necessarily both, developing connections and equivalences will be useful for answering open questions in both mathematical formulations of CFT.