The definition you probaby know for the word "norm" is "something that is usual, typical, or standard." But there is actually a mathematical definition for it as well: "the product of a complex number and its conjugate, equal to the sum of the squares of its real and imaginary components, or the positive square root of this sum." (Source)
Let's break that down!
Wolfram Math World explains it a little further: "The norm of a mathematical object is a quantity that in some (possibly abstract) sense describes the length, size, or extent of the object."
So when can we use a norm and how can we identify it?
A helpful Pinterest page uses this diagram:
It is used practically, for example, when cities are planning things like taxi routes and the best way to reach your destination in the shortest amount of time. A map of that would look something like this:
(Source)
