Curl

In vector calculus, the curl is a vector operator that describes the infinitesimal rotation of a vector field in three-dimensional Euclidean space. At every point in the field, the curl of that point is represented by a vector. Curl is an extension of torque.

Given a vector field ${\displaystyle \mathbf {F} }$, the curl of ${\displaystyle \mathbf {F} }$ can be written as ${\displaystyle \operatorname {curl} \mathbf {F} }$ or ${\displaystyle \nabla \times \mathbf {F} }$, where ${\displaystyle \nabla }$ is the gradient and ${\displaystyle \times }$ is the cross product operation.[1][2]