We are moving into the web development module; become familiar with it.
What is the structural layer?
The structure or content layer of a web page is the underlying HTML code of that page. Just as a house's frame creates a strong foundation upon which the rest of the house is built, a solid foundation of HTML creates a platform upon which a website can be created. (ThoughtCo.)
To be prepared for a discussion of the second of several web page layers, read over the following:
You may, of course, read other lessons, if you wish.
You will probably come back to them often, so you might want to bookmark the site.