JavaScript doesn't have cross-browser compatible functionality which is why a developer has to write code manually to implement the functionality. Whereas the cross-browser code compatibility is inbuilt in jQuery.
JavaScript requires long lines of code to code a functionality whereas in the case of jQuery, just import the library and call the functions which would reduce the programmer’s effort in coding.
JavaScript is an interpreted language written in C and is a combination of ECMAScript and DOM whereas jQuery is a JavaScript library developed to run things faster and make things simplified for JavaScript. jQuery doesn't have the ECMAScript.