I checked their website and I still don't get what it actually is. I'm familiar with Hugo (compiles .md files to static site), Forestry (CMS for Hugo and other

I checked their website and I still don't get what it actually is. I'm familiar with Hugo (compiles .md files to static site), Forestry (CMS for Hugo and other static site generators) and Netlify (to deploy that static site). Where does it sit, and how is it different?