Abstract: Let D be the sheaf of differential operators on a complex manifold M. If we turn on the Planck parameter, the ring D becomes a deformation quantization of the cotangent bundle of M. There is an analogue to this operation on the Betti side. Namely, we can "turn on the Planck parameter” for constructible sheaves. The resulting concept is called sheaf quantization. This concept (originally introduced by Tamarkin) has proven useful in many areas. In this talk, I will give an introduction to the concept, including applications to symplectic topology, WKB analysis, RH correspondence, etc.