If you do not know what the file protocol is it is a way to load an html document, or other assets into a web browser that is stored locally on your computer. In other worlds loading a file in a web browser by way of file:\/\/ rather than https:\/\/. This might not be the best way to go about doing things as in some situations you will run into problems that have to do with the use of the file protocol, but it can still be thought of as a stepping stone to using https that will result those problems.
Now that we have a hello world out of the way lets move on to something else such as event attachment. There is a number of ways to attach a wide range of various types of events to elements in html. However for this getting started post I thought I would stick to just a basic example that has to do with just the click event and the add event listener method.