Var names with jQuery so a dollar sign before it

I see that on some codes use dollar sign before the name like

var $thisone = $(’.thisone’);

On both side need to set dollar sign? like in var names and where to use it?

Or hiw its going on if stay simple var names?

Thanks.

Jquery shorter sign.
You become with that later. https://www.w3schools.com/Jquery/default.asp
To use you must declare

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>

It is used to make it clear the variable is a special jQuery object vs a normal DOM element. It is strictly informational only. You could just as easily write:

var thisone = $(’.thisone’);

Thanks!

Still a question when use var names in a function that means is have only in function so that can use in another function a name and set another value for it?