If the tags are anything like DWM or Awesome, they're like traditional workspaces like you'd find in Gnome or KDE, but with the option to display multiple workspaces at the same time.

Example:
You have a "coding" tag that contains your editor and terminal, and a "browsing" tag that contains Firefox and Chrome. You can display the windows in just "coding" or "browsing," or you can display all windows from both tags at the same time.

I tried to upload a bigger image but Lemmy wasn't allowing me to do so with 'file too big' error. I like Yambar cause its easier to customize it with custom scripts (like having a script to show how many packages to update) and also the feel of it is different and interesting to use.

Edit: I now have added a link for a higher res version of the image in the description 🤙