SEO involves making Web pages more search engine friendly to promote them as the most relevant solutions for the search engines' users. The improvements can mean the difference between achieving top rankings, which can result in thousands of monthly visitors, and being lost in oblivion.

Search engine optimization is basically about following search engine rules. If your Web page fits the criterias that a search engine considers the most important factors in terms of relevance, then it will reward you with a top ranking. Search engine optimizers simply modify Web pages to fit these criterias. This gives the Web pages a better chance of being selected by the search engines as the most relevant page for the search query.

The Internet is basically a massive disorganized library. Search engines are like librarians. They both try to organize the content, so that people can find what they're looking for without too much effort. With books, librarians have the benefit of bibliographic databases and the information on the book covers to help them organize their library.

Search engines don't have such a luxury. There aren't databases of every single Web page ever created. The Internet is just too big. There's too much information to index. The only way a search engine can try to organize the mass of information available on the Internet is by the use of keywords and links.