A condominium is a separate property with a real title. A co-op is an ownership share in a corporation that owns an apartment building, coupled with a long-term lease between the occupant of a unit and the corporation that owns the building.
Different states have different laws, and for some reason I think New York State law is more favorable than others for co-op arrangements ... which is why there are so many of them in New York City.
I have always heard of co-ops in NY, but never here in CA. I don’t think we have them.