Drupal nodes 101
A node is a unique ID number assigned to pieces of content saved in Drupal. This is essential when searching for and linking to content within Drupal.
How to use nodes
Do not paste internal URLs into Drupal fields. It is always best to type in the content's Drupal title, also known as the internal path, and confirm the node number. This guarantees that links will not break if there are any changes to the structure of the URL.
Note: if you are linking to an external site, you can paste in the full URL into the Drupal field.
Where to find the node
To identify the node number, edit into the page and refer to the URL.
Another method is to hover over the Edit button in the main Drupal Content menu and look for the URL to appear in the bottom left of your browser window.