Disclaimer: I'm not and English native speaker and there's no equivalent in my language, in fact they usually are not translated and used in English. (I mean, there is an equivalent, but it's never used in this context)<p>My position about this issue is ambivalent.<p>From a purely human standpoint I understand it, truly.<p>When we use those terms referring to tools, I don't see much sense.<p>When men used bulls to pull the plough it really was a master-slave relationship<p>The bull could not be the master, even if it wanted too, a human is not strong enough to pull the plough effectively<p>It's a symbiotic relation between two elements where one is in charge of the "intellectual" part and the other of the physical one.<p>We can use controller and agent, but controlling is problematic too<p>We can use manager and worker, but it still implies that there's a disparity between the two<p>Frontend/backend doesn't fully capture what's going on<p>We use master/slave because one side is taking all the decisions, the other is just obeying<p>It's bad, I recognize it, and maybe it's time to change, but no amount of re-wording will change the fact that it's mainly used nowadays for tools that work that way, not for people.<p>Maybe leader/follower looks like a better choice, but really isn't, follower sounds more dumb to me, at least slaves rebelled throughout history, followers don't. And a leader can be as bad as a master who owns slaves.<p>Main/secondary is somewhat the best of them all, but it only works for systems were any secondary node can be promoted to replace the main in case of failures, which is not always the case.<p>Bull/man is not main/secondary for example.