Vector calculus is often considered a prerequisite or co-requisite for studying partial differential equations (PDEs) due to its foundational role in multi-variable calculus and its relevance to key concepts in PDEs, such as the Laplacian operator, which is derived from vector calculus operations. While some argue that vector calculus is not strictly necessary, it provides significant benefits for understanding and solving physically relevant PDEs, including the Maxwell Equations and Einstein field equations, where geometric interpretations and symmetries are crucial. The discussion also highlights that while linear algebra, multivariable calculus, and ordinary differential equations (ODEs) are essential prerequisites for PDE courses, vector calculus can enhance comprehension and application of these mathematical concepts. Some participants note that the inclusion of vector calculus in prerequisites may vary by institution, with some courses integrating essential material from vector calculus into their curriculum.