jQuery works by using functions, a library, written in JavaScript. You can use these functions to write powerful things without actually typing much code. jQuery is very lightweight and efficient so you don’t have to worry about it slowing down the user experience. Referencing jQuery is extremely easy and there are multiple ways to do it. Remember that you can reference JavaScript from anywhere. You could even take the JavaScript that I am writing for this website and use it. The first way uses this principle. Google has a jQuery library available for all developers to use.