Lecture
This lecture introduces the concept of divergence in vector calculus, which is a differential operator similar to the gradient but in the opposite direction. The divergence takes a vector field and produces a scalar field by summing up the derivatives of each component. An example is provided to illustrate the computation of the divergence of a three-dimensional vector field. The instructor emphasizes that the divergence is only applicable to vector fields and highlights the key points to remember about its computation.