Another facet of SEO to consider before you build your web site is the elements needed to ensure that your site is properly indexed by a search engine. Each search engine places different importance on different page elements. For example, Google is a very keyword-driven search engine, but it also looks at site popularity and the tags and links on any given page. How well your site performs in a search engine is determined by how the elements of your page
meet the engine’s search criteria. Every search engine looks for the following main criteria:
■ Text (meaning keywords)
■ Tags—both HTML and meta tags
■ Links
■ Popularity
Text
Text is one of the most important elements of any web site. Of particular importance are the keywords within the text on a page, where those keywords appear, and how often they appear. This is why keyword marketing has become such a large industry in a relatively short time. Your keywords make all the difference when a search engine indexes your site and then serves it up in search results.
Keywords must match the words and phrases that potential visitors will use when searching for your site (or for the topic or product that’s listed on your site). To ensure that your keywords are effective, you’ll need to spend some time learning which keywords work best for your site. That means doing keyword research and testing the keywords that you do select to see how effective they really are.
Tags
In search engine optimization, two kinds of tags are important on your web site: meta tags and HTML tags. Technically, meta tags are HTML tags; they just appear in very specific places. The two most important meta tags are the keyword tag and the description tag.
The keyword tag occurs at the point where you list the keywords that apply to your web site. A keyword tag on a search engine optimization page might look something like this:

The description tag provides a short description of your page. Such a tag for the search engine optimization page might look like this:

Not all search engines take meta tags into consideration because in the past, these tags have been overloaded with keywords that were irrelevant or inaccurate. For that reason, your site should use both meta tags and other HTML tags. Some of the other HTML tags that you should include on your web site are the title tag, the top (or H1) heading tags, and the anchor tags.
The title tag is the tag that’s used in the title of your web site. This tag will appear like the following: