You can think of a tag as a container to hold whatever data you want to better understand. For instance, we've created a tag for each of our core users so everyone in our company can better understand each individual power user.
Second: what's a grouping?
We've also created what we call a "grouping," which is a group of tags. In this case, we created a grouping called "project puppy," which includes all the core users so we can understand them as a whole.