Great.
I always try to remember myself to use terms like Steem blockchain or Steem platform for the ecosystem and the term frontend for Steemit, busy and other interfaces.
The challenge is that there is a company called Steemit Inc. which people take as a synonym for the platform. Which once was true yet it is no longer so.
Steem as a platform is much more than Steemit Inc., lukcily. Without the third party tools and without the community this platform would be gone by now.
Thanks a lot for your suggestion! That's really helpful. It seems liek the term "Steem Platform" sounds more comprehensive than the Steem blockchain.
Yes, it covers much more.
Blockchain is the bottom layer, the base technology.
Platform is the base technology and the upper layers.
Ecosystem is platform with third party tools, users, community, ... everything.
OK, these definitions might be a bit vague but they are pretty good, I think.
That's much clear! Many thanks for your help!