The Open Source Definition and Free Software Definition are virtually identical in application. Other than CC0 being withdrawn from OSI consideration (not denied) and accepted as a Free Software license, I can't think of any differences in practice.
The Open Source community and the Frr Software community have differing ideologies, but nearly identical minimum requirements for software licensing to meet those different visions.
Now as per my original point. This has been going on a long time, and as with language the definitions can change over time.
Early on they were different. Open Source basically implying "hey you can read the Source!" but not necessarily giving you any other freedoms to actually USE it.
But today, people are saying Open Source and Free Software are much the same thing.
I am all for them being the same thing. IE I am happy with Open Source in all practical ways having the same freedoms as Free Software.
But now we gotta call out those projects which define themselves as "Open Source" for marketing use of the goodwill around nice modern definition while operating under the old definition.
Edit: for clarification
The companies who have restrictions on how their Open Source software can be used can technically be Open Source (depending on your definition) while failing to be Free Software.
The two links clarify that originally at least, they were not the same thing.
This has been going on for a long time and hence as with many language phrases the use/connotation/definition may change over time.
And so we have a HN comment fest over "What Really Is The Definition of Open Source?".