information:classification
Norm

The norm of a vector is represented with double bars on both sides of the vector. The norm of a vector v can be represented as: ‖ v ‖ {\displaystyle \|\mathbf {v} \|}

The norm is also sometimes represented with single bars, like | v | {\displaystyle |\mathbf {v} |}, but this can be confused with absolute value (which is a type of norm).