LSI keywords (Latent Semantic Indexing) are basically keywords that are semantically related to your primary keyword. Contrary to popular belief, they are NOT just synonym or keywords that are similar in meaning.
Keyword stuffing is the practice of inserting a large number of keywords into Web content and meta tags in the attempt to artificially increase a page's ranking in search results and drive more traffic to the site.
A Sitemap is an XML file that lists the URLs for a site. It allows webmasters to include additional information about each URL: when it was last updated, how often it changes, and how important it is in relation to other URLs in the site. This allows search engines to crawl the site more...