what is 24 in jquery

1jQuery is a lightweight, "write less, do more", JavaScript library.
2
3The purpose of jQuery is to make it  much easier to use JavaScript on
4your website. 
5
6jQuery takes a lot of common tasks that require many lines of JavaScript code
7to accomplish, and wraps them into methods that you can call with a single
8line of code.

1$ is the shortcut for jQuery and acts as a selector. Similar to querySelector
2$('#id')
3$('.class')
4$(this)

1$ is alias to jquery by default. In the place of $ we can use Jquery by default. Jquery is almost simplying code of js this is too we can consider as simplification of code.