Why I always see this lines of code at the begining of almost any webflow project that uses jQuery?

Community resources
1

cannout you use jQuery without it?

var Webflow = Webflow || ;
Webflow.push(function () {

});

2

You can use jQuery anywhere in the before /body custom code area, since jQuery is loaded just prior to that.

Using the Webflow.push construction above is common practice since it fires when the DOM is loaded and Webflow.js is loaded… that ensures that [ pretty much ] anything you could need to access in your jQuery script is ready to use.