Question:

When creating an article, you have the option to specify labels for the article. After you create the article, you can also add search words from the search tab. What's the difference between labels and search words? Are they weighted differently?

Answer:

Labels are used in user and agent search. They are treated as just another piece of the article's content and aren't weighted any differently than other words in the article.

Search words are different. They are only used in the user interface search. Any time a user's search matches a search word on an article, that article is always shown at the top of the search results, regardless of what its normal ranking would be.