When prospective visitors go to a search engine to find information, they type a few identifying keywords that describe what they're looking for. The more those words are honestly reflected on your page, the better your chances are that your page will appear in a search engine's results. So, it's a good idea to think about what your page is about, decide on some keywords that describe your page (and that might be used to find it), and then use your keywords consistently.
Figure 24.1. In this document, I've used the keywords Barcelona and market in the title, headers, alternate text for images, and in the first paragraph. Try searching for Barcelona market on Google.
Figure 24.2. Use keywords as consistently and naturally as you can. If you do it right, there's no reason to cheat.