I think it was explained to me as the ability to tag certain windows with short descriptors and then assign tags or groups of tags to different displays/layouts/panes. The main reason I haven't tried it because I had already switched to Sway and gotten rid of Xorg entirely.

I think the great part is being able to assign multiple tags to a window so it appears under multiple workspaces (same toolbelt as a sticky tag, which can co-exist), and being able to assign multiple tags to a workspace ("Chat" and "Music"). The ability to toggle your music windows in and out of existence, independently of other contexts, feels more like having every window on a hotkey than switching to another entire workspace or using sticky. It abstracts your contexts out from your workspaces and allows you to preform manipulations across those sets. I don't think dwm would let you show the difference (https://en.m.wikipedia.org/wiki/Difference_set) between two tags without a patch (because why?), but if you wanted to you could.