I've had some questions about the differences between and uses of tags and labels in the community. I thought I had a document on the topic, but it turned out to be mostly technical SEO recommendations for web people.
Anyway, Labels, in the community site can only be created by admins, or blog authors. They are meant to be used by general users as pre-defined categories. So you find the Label, click on it, and you get a bunch of articles with that label assigned. Users can also subscribe to a label, so if a new message labeled "sketch" is written and you subscribed to the label "sketch", you will be notified.
Tags are names that can be applied by end users to articles or posts that they or other people have written. They help produce search results. So you find an article that you find helpful on the topic of Piping. So you tag that article Piping. And later you can search on Piping, and get that article back as a result. Piping might turn out to be a common term that many other people would use, so if you wanted to, you could personalize your tags by tagging things "mjlPiping", with your initials or some code that isn't common. That way you could make your own personalized indexing system on the community. I don't know of anyone who actually does this, but it's possible, and would be useful if you had the discipline to use it regularly.
Think of both labels and tags as if they were keywords. Tags are just a free-for-all keyword where anyone can create their own, and labels are keywords that only admins can control, and (ideally) minimize and organize in a way that makes sense, and of course you can subscribe to labels. I think the NX area has made extensive use of labels. The Solid Edge Blog and Knowledge Base both use labels, but not in a highly organized way. This differentiation between tags and labels is not some internet standard, it is just how the people who run the platform that the community is based on have chosen to do things. If you go to a site based on Blogger, or Wordpress, or Joomla, things will be different.
Notice how it has "Everyone's tags"? This means some random readers have tagged this article in a way that means something to them so they can find it later. Or Dave may have tagged it himself, but tags are for users/readers. Dave did apply several labels, however, and these show up as buttons. If you click one of the buttons, you go to a set of search results that show other articles labeled with the same word.
Both Tags and Labels will show up in Google search results and affect SEO. So it does help the community from a Google search results sort of perspective if everyone applies common tags to as many articles as possible. This will make the community improve in search result standings in Google searches. Probably Yahoo and Dogpile as well, who knows.
From a community end user point of view, I think that's what you need to know about labels and tags. If you have any questions, I'll try to answer them. One question you might ask is "Why does the right column waste so much space with Labels if we don't really use them?" Well, that's a good question. I'm looking at tweaking the recent community redesign to see if we can't make it more tailored to how we here use the community, which will include more efficient use of space.
Retired Community Manager for Solid Edge. This account is no longer active.