The main purpose of this article is to make sure that all basic HTML Elements are decorated with CSS so as to not miss any possible elements when creating new themes for Hugo.
Featured image is the image that appears on summaries at the list pages and the top of content pages. Every content page in this theme can have a featured image.
Hugo uses the excellent Go html/template library for its template engine. It is an extremely lightweight engine that provides a very small amount of logic. In our experience that it is just the right amount of logic to be able to create a good static website. If you have used other template systems from different languages or frameworks you will find a lot of similarities in Go templates.