What are relationships?

After Jim and Lynn had gotten their coffee, they sat down at a table and Jim got out his pad of paper. "Let's take a look at the relationships between the various content types you have defined on your site." He drew a diagram that looked like this:

Blue Drop Realty content type relationships

Blue Drop website relationships

"Okay, your site has four main content types: Property, Realtor, Property Owner, and Open House. They are related to each other, so the field_property_realtor in Property references the Realtor nodes, the field_property_owners in Property references the Property Owner nodes, and the field_open_house_property_refe in Open House references the Property nodes.

There are two other entity references that Drupal created for you when you put taxonomy term fields in your content type. This is a bit of a change from Drupal 7, but mostly in terminology since everything in Drupal 8 is an entity, whereas in Drupal 7, taxonomy terms were still partly special.

Entity...