Functions in JavaScript/jQuery

Question

Suppose we attached any function like keypress(in jQuery) or addEventListener(in JavaScript) then does they get permanently attached to that element and we do not need to call them every time.
PS: It may should funny question but I am new to JS and it appears very different from Python.

Answer 1

It's best not to rely on jQuery. Complete JavaScript and know it very well that's the best.
http://youmightnotneedjquery.com
So learn JavaScript very well.
It's just my opinions

Answer 2

It's best not to rely on jQuery. Complete JavaScript and know it very well that's the best.
http://youmightnotneedjquery.com
So learn JavaScript very well.
It's just my opinions

Answer 3

Yes setting any event is always attached to the element

Answer 4

Should only have to declare it once