We all know what content is...sort of. This book is made up of content. This chapter contains content, as does this section within this chapter. The more important question is: what is it in the context of Drupal? This question is best answered with the home page as an example, because you'll know it when you see it!
The following screenshot shows a piece of content that I added to the site, in the main content area, with a thick rectangle around it:
When rendered and displayed in the browser, it's simply content, but up until that point, it is content of a certain type, of a content type, also known in Drupal as a node bundle. Does Drupal look at this content simply as:
Chapter 2 - Understanding Content Types
We all know what content is ... sort of. This book is made up of content. This chapter contains content, as does this section within the...