Search engine optimization is the art and science of making web pages more attractive to internet search engines. Some internet businesses consider search engine optimization to be a subset of search engine marketing.
In the mid-1990s, webmasters and search engine content providers began optimizing websites. At the time, all webmasters had to do was submit a URL to a search engine, which would then send out a web crawler. The crawler would extract links from the webpage and use the information to index the page by downloading it and storing it on the search engine’s server. Once the page was stored, a second program, called an indexer, extracted additional information from the webpage and determined the weight of specific words. When that process was complete, the page was ranked.
It did not take long for people to recognize the importance of being highly ranked.
In the beginning, search engines used search algorithms based on information webmasters provided about their web pages. Webmasters soon began abusing the system, which required search engines to develop a more sophisticated approach to search engine optimization. Search engines created systems that considered several factors, including domain name, text within the title, URL directories, term frequency, HTML tags, on-page keyword proximity, Alt attributes for images, on-page keyword adjacency, text within NOFRAMES tags, web content development, sitemaps, and on-page keyword sequence.
Google developed a new concept for evaluating internet web pages called PageRank. PageRank weighs a web page’s quantity and quality based on the page’s incoming links. This method of search engine optimization was so successful that Google quickly began to benefit from strong word of mouth and consistent praise.
To help discourage abuse by webmasters, several internet search engines, including Google, Microsoft, Yahoo, and Ask.com, do not disclose the algorithms they use to rank web pages. The signals used today in search engine optimization typically include keywords in the title, link popularity, keywords in links pointing to the page, PageRank (Google), keywords that appear in the visible text, links from one page to inner pages, and placing the punch line at the top of the page.
For the most part, registering a webpage or website with a search engine is a simple task. All Google requires is a link from a site that is already indexed, and its web crawlers will visit the site and begin to spider its contents. Usually, within a few days of registering with the search engine, the main search engine spiders will begin to index the website.
Some search engines will guarantee spidering and indexing for a small fee. These search engines do not guarantee a specific ranking. Webmasters who do not want web crawlers to index certain files and directories use a standard robots.txt file. This file is located in the root directory. Occasionally, a web crawler will still crawl a page even if the webmaster has indicated that the page should not be indexed.
