As a fairly experienced Drupal 7 developer, I'm thrilled by all the new goodies in Drupal 8, but haven't quite figured out the relationship between entities and the new plugin system.
I've followed a number of tutorials on both topics, but haven't come across how they would fit together? Do they fit together?
I'd be very grateful for an explanation of how these two features coexist and inter-operate within the Drupal 8 ecosystem.
My specific use case
To clarify my question: I'm building a module that provides a method for the site owner to display alerts to their visitors. I've created a new custom Content Entity (cleverly called 'Alert') using Drupal Console and custom code.
I've also followed along with several tutorials that describe how to create a custom plugin type and found this idea exciting, but the gap in my understanding is this: when (or if) there would be a use case for combining a custom Content Entity with a custom plugin type. Does anyone have an example?