Explore a categorical interpretation of the GKZ D-module in this advanced mathematics lecture. Delve into the B-side category in toric homological mirror symmetry, focusing on the strata of the characteristic cycle of the associated GKZ D-module. Examine various consistency checks and learn about the construction based on the string theoretical work by Aspinwall-Plesser-Wang. Cover topics such as combinatorial context, geometric meaning, BB GKZ, moduli space, mirror map, deformed stack, direct connection, sheaves, discriminant, spherical functor, and triangulation. Gain insights into this complex mathematical concept through examples and observations presented by speaker R. Paul Horja from IMSA.