The process of choosing targeted keyword phrases related to a site, and ensuring that the site places well when those keyword phrases are part of a Web search.
There is much confusion about search engine optimization (SEO) and its relation to search engine spamming. Generally, legitimate search engine optimization adds to the user experience, while search engine spamming takes away from the user experience, although there is much gray area between the clear-cut examples on either side.
Optimization involves making pages readable to search engines and emphasizing key topics related to your content. Basic optimization may involve nothing more than ensuring that a site does not unnecessarily become part of the invisible Web (the portion of the Web not accessible through Web search engines). Advanced optimization may include significant research into every element of page design, site structure, and off-the-page criteria.
Before pages can be optimized, research must be done to determine which keywords to target. This involves finding relevant keywords, determining their popularity, assessing the amount of competition, and deciding which keywords can be best supported with quality content.