Divergence and Curl (Vector Fields)

Gradient, Divergence, and Curl Explained: Essential Vector Calculus

Div, Grad, and Curl: Vector Calculus Building Blocks for PDEs [Divergence, Gradient, and Curl]

Unit vectors | Vectors | Precalculus | Khan Academy

Vectors Introduction for Beginners

The Vector Cross Product

Vector dot product and vector length | Vectors and spaces | Linear Algebra | Khan Academy