Vector

A Primer on Matrix Calculus, Part 1: Basic review

In this paragraph:

>In single variable calculus, the chain rule can be written as . In the multivariable case, for a function , we write where is the partial derivative of with respect to its th argument. This can be simplified by employing the following notation, which uses a dot product: .

What does stand for?

My understanding that g maps and indicates i-th element of a vector that g produces.

Is that the right way to think about it?

3blue1brown touches on that way of thinking about functions/derivatives in this video

(very similar to Khan academy video linked in the article)