They have heavy overlap, one is not a subset of the other, and they are similarly restrictive, just shepherded by different groups. I’m sure there are licences that satisfy one but not the other, but they would have to be few and far between; just reading through each it’s not obvious how one could satisfy only one definition.
Open Source Software follows the Open Source Definition, while Free Software follows the Free Software Definition.
They have heavy overlap, one is not a subset of the other, and they are similarly restrictive, just shepherded by different groups. I’m sure there are licences that satisfy one but not the other, but they would have to be few and far between; just reading through each it’s not obvious how one could satisfy only one definition.