∇ × F records the infinitesimal circulation of a vector field at every point.
Integrated over a surface the same quantity becomes net rotation through that surface, and Stokes’ theorem converts it back into a line integral around the rim:
∮_∂S F · dr = ∬_S (∇ × F) · n dS.
Green had already written the planar version in 1828; the three-dimensional statement first appeared as an examination question set by Stokes in 1854.
The identical local-to-global translation governs the divergence theorem and the four compact field equations Maxwell assembled a decade later.