In order to get the most out of Drupal with the least confusion, a basic understanding of some concepts is needed; the most important of these is 'content', because we're working with a Content Management System.
We can surely answer a simple question such as "Is a paragraph of text, content?" However, while we might consider a paragraph of text to be content, with Drupal, the answer to that question is: "It depends".
Opinions on how best to express what is, and is not, content in Drupal vary greatly. It helps if we differentiate 'content' from Drupal content. We can certainly say that 'content' is any material that makes up the web page, be it Drupal-generated content, such as the banner and buttons, or user content, such as the text of a blog. Within Drupal, 'content' has more narrow parameters.
When you create a story in Drupal, it is stored in a database as a node, and is assigned a node ID (nid). Some would say that, with respect to Drupal...