Can some one explain please, what is velocity curl?

Thanks is advance

CFD newbie

http://www.cfd-online.com/Wiki/Vorticity

Curl of a velocity represents the rigid body rotation part of the velocity gradient near a point.

actually a differential change of velocity near a point is divided into three parts, linear translation rigid body rotation deformation = linear deformation + angular deformation

so the rigid body rotation part is termed as curl of velocity.

Thanks guys. That was helpful.