![](/static/61a827a1/assets/icons/icon-96x96.png)
![](https://fry.gs/pictrs/image/c6832070-8625-4688-b9e5-5d519541e092.png)
Master in branch meant the same as the master of an audio track or video. We haven’t all stopped saying “remaster” or “masterpiece”.
As it turns out, there are software developers from outside the country with people whose grandparents-grandparents were chattel slaves, and they name things without the same baggage. It’s Gulf of America stuff, but for the ‘good guys’.
The point is that no branch was ever called a slave branch, just as no audio copy was ever called a slave copy. One does not direct the other in the same way that master and slave implies. Usually quite the opposite.
Oh and master-slave usually refers to hardware infrastructure, not programming. Where, as you mentioned, client-service is the equivalent, or parent and child.