Higher Order Arrow Functions percent sign

I am on the “Higher Order Arrow Functions” section for Javascript and the solution included punctuation and functions that have not been discussed yet.
What does “%” do in Javascript?
const squaredIntegers = arr.filter( (num) => num > 0 && num % parseInt(num) === 0).map((num) => Math.pow(num, 2));

I figured out what “Math.pow()” does from google. This function was not yet discussed in the lessons either.

Thanks for the help!

You might want to go back to the Basic JavaScript section to see what it does.