What is the DOM?
DOM is the document object model, a tree-like structure created by browsers so we can quickly find html elements using javascript.

What is JQuery?
Because different web browsers have different interfaces jQuery is used to write code that interacts with all modern web browsers.

How do we include JQuery on our page?
By including jQuery in our project directory, then include it in our html with a line like "<script src="jquery.min.js"></script>" and finally by using a "myscript.js" file 
where we write our jQuery code and including it in our html with the like "<script src="myscript.js"></script>".

What is the document.ready function and why do we need it?
If our jQuery code run before the DOM is ready it will have no effect, that's why we are using this function to have our code run when it gets the signal that the DOM is ready.

How do we select HTML elements using JQuery?
elements: $("h1")
id: $("#myid")
class: $(".myclass")