What is the relationship between "canned" forms and custom Corvid forms?

I started experimenting with some “canned” forms (e.g. contact form) that populated a “submission table” and optionally sent an email. This was very easy to setup, and worked as advertised, but not quite what i needed.

So I started to investigate Corvid, and saw how I could create my own forms from scratch, and use Javascript to customize the processing. So I wanted to see how this related to the “canned” forms I had created. From the content manager, I could see “collections” that corresponded to the “canned” forms I had created, but they had no data in them, although the “submission tables” did show the data I expected. I also saw no event handlers. Should I view the “canned” forms as having some internal implementation that has no real correspondence to stuff built using Corvid?