But in this context you seem to imply that there are practical differences i.e: Not all Open Source licences are considered Free Software in the practical sense.
The Open Source Initiative (OSI) was certifying all sorts of licenses as "open source" under their definition. Basically if you allowed people to see your source code it was considered open source. That's not really practical and most open source licenses had an agenda of the company retaining control, which means people can't really do what they want. To most developers there are basically the BSD/MIT licenses that allow you to do whatever you want, and the GPL/LGPL licenses that allow you to do what ever you want - so long as you pass that freedom on to your users. These are both forms of Free Software, though the distinction causes much argument. Every other "open source" license is generally more restrictive and meant for someone to retain ultimate control, including the old Microsoft licenses.
In my opinion the OSI did more harm to the movement than good by "certifying" a huge number of irrelevant licenses so companies could claim be doing the cool new thing. None of that code can be integrated into anything else under different terms - at least not without consulting a lawyer.
