difference between omz "plugins" and "themes"? What exactly is the difference, _operationally_ , between plugins and themes in oh-my-zsh? I.e. how would things break (if at all) if a plugin were instead put among the themes, or a theme among the plugins? Or is the distinction purely organizational?

Both the theme and the plugins are sourced in `oh-my-zsh/oh-my-zsh.sh`, so technically there should be no difference.

But a theme should only be used to change the appearance and a plugin is there to add new functionality.

With appearance I mean setting the values of `$PS1`, `$PS2`, `$RPS1` and etc.

There are some plugins which also set some appearances, like the vi-mode plugin which sets the right hand side prompt (`$RPS1`) when it is not already set.