JQuery is a framework designed to make Javascript easier to use. Uses methods to minimize the number of lines it takes to write the code.
The library is a complete list of all the different methods that JQuery utilizing to run Javascript code simplier.
Quicker to write, shorter code, popular framework, lots of support and resources, and if you can't find a method that you want to use..you can write own code in JS
can take up lots of space kb-wise, library can be hard to understand, older framework so newer ones are getting attention
JQuery Content Delivery Network(CDN)- If you don't want to download and host jQuery yourself, you can include it from a CDN (Content Delivery Network). Both Google and Microsoft host jQuery. Attach the script in the header.
Production version-using your live site for production--not recommended
Development version--downloading a local copy
JQuery works on top of Javascript code. Without JS, there would be no JQuery.