What is the purpose of the Nabla Operator?

Question

Plain english, please.

Answer 1

The Nabla operator means that an operation takes place on all the elements of a vector.

Gradient, divergence and curl all use the nabla operator.

It is represented by an upside-down triangle. In vector calculus, del (or nabla) is a vector differential operator.

The word itself is thought to be derived from the Greek for harp.

Answer 2

It is shorthand for (sum over i) e_id/dx_i, where e_i is the ith basis vector and x_i is the ith coordinate.