There’s an interesting discussion on this blog and Slashdot over Google’s inconsistent use of the terms “tag” and “label” across its various products when allowing users to add descriptive keywords to pieces of content. Google uses the term “label” for Gmail, Blogger, Bookmarks, and uses the term “tag” for Google Docs & Spreadsheets, Google Video and Picasa.
The term itself doesn’t matter much, although the rest of the web has pretty much settled on the use of “tag” as the way to describe descriptive keywords on content. Google’s inconsistency in tag v. label is probably a sign of product group autonomy and a big “who cares” at the senior level. They can call it “frogs” for all I care, as long as they keep the feature at Gmail.