Here are some of the concepts you should keep in mind:
First of all, they can all be encapsulated within an HTML page, meaning that the browser starts by loading an HTML page, and only then it knows what to load from there.
For those who wish to learn via video here is a quick video tutorial which covers all:
W3School Tutorial for HTML
W3School Tutorial for CSS
Atom (Free) Editor
Notepad++ (Windows only)