To be clear, Open Source and Free Software aren't licenses. They are philosophies. FOSS licenses come in two major varieties - copyleft (like GPL) and permissive (like MIT). It's possible for either type of license to conform to both open source and free software philosophies. In fact, the vast majority of FOSS licenses - both copyleft and permissive - are endorsed by both camps (OSI and FSF). Also, both camps reject licenses for similar reasons - like for having proprietary terms (as in case of BSL).
The property of being able to keep changes to oneself is the property of permissive licenses, not opensource. Open source software under copyleft licenses cannot be modified and distributed while withholding changes. The inverse is applicable to FS under permissive license too.
The real difference between free software and open source is in how they treat the software. FS camp considers software as something that should give the users total freedom over the computing devices they own. The software shouldn't constrain or exploit the end user in any manner. This of course needs the source to be open.
OSS camp established open source because they realized the advantages of 'open' source, but didn't like the emphasis on freedom. That's more in line with corporate philosophy - take advantage of unaffiliated talent to increase code volume and quality, without making any commitment to user freedom. This is why many companies completely avoid the term free software. It's also easy to find 'open source' code that's very exploitative towards users, despite being open and using FSF-endorsed licenses.
The property of being able to keep changes to oneself is the property of permissive licenses, not opensource. Open source software under copyleft licenses cannot be modified and distributed while withholding changes. The inverse is applicable to FS under permissive license too.
The real difference between free software and open source is in how they treat the software. FS camp considers software as something that should give the users total freedom over the computing devices they own. The software shouldn't constrain or exploit the end user in any manner. This of course needs the source to be open.
OSS camp established open source because they realized the advantages of 'open' source, but didn't like the emphasis on freedom. That's more in line with corporate philosophy - take advantage of unaffiliated talent to increase code volume and quality, without making any commitment to user freedom. This is why many companies completely avoid the term free software. It's also easy to find 'open source' code that's very exploitative towards users, despite being open and using FSF-endorsed licenses.