What is Search Engine Optimization
Written by Suresh Mishra   

Search Engine Optimization (SEO) is considered the more technical part of Web marketing. This is because SEO helps in the promotion of sites and also requires  technical knowledge – at least familiarity with HTML. SEO is sometimes also called SEO copyrighting because most techniques used to promote sites in search engines deal with text. SEO is the activity of optimizing Web pages or entire sites to make them search engine-friendly, thus getting higher positions in search results.

You can be included in paid search results for given keywords but basically the idea behind the SEO techniques is to get top placement because your site is relevant to a particular search term, not because you pay. 

If you are a leader for rare keywords, then you do not have a lot to do in order to get decent placement. But in most cases you need to pay special attention to SEO and devote  time and effort to it. Even if you plan to do some basic SEO, it is essential that you understand how search engines work and which items are most important in SEO.

How Search Engines Work

Unlike humans, search engines are text-driven. Search engines crawl the Web, looking at particular site items (mainly text) to get an idea what a site is about. Search engines perform several activities

  1. Crawling
  2. Indexing
  3. Processing
  4. Calculating
  5. Relevancy
  6. Retrieving.

First, search engines crawl the Web to see what is there. This task is performed by e piece of software, called a crawler or a spider (or Googlebot, as is the case with Google). Spiders follow links from one page to another and index everything they find. It is impossible for a spider to visit a site daily just to see if a new page has appeared or if an existing page has been modified. Sometimes crawlers will not visit your site for a month or two, so during this time your SEO efforts will not be rewarded. But there is nothing you can do about it, so just keep quiet.

Crawlers do not see images, Flash movies, JavaScript, frames, password-protected pages and directories. These will not be spidered, not indexed, not processed, etc. -  they will be non-existent for search engines.

After a page is crawled, the next step is to index its content. The indexed page is stored in a giant database. Essentially, the process of indexing is identifying the words and expressions that best describe the page and assigning the page to particular keywords. Sometimes they might not get the meaning of a page right but if you help them by optimizing it, it will be easier for them to classify your pages correctly and for you – to get higher rankings.

When a search request comes, the search engine processes it – i.e. it compares the search string in the search request with the indexed pages in the database. Since it is likely that more than one page (practically it is millions of pages) contains the search string, the search engine starts calculating the relevancy of each of the pages in its index to the search string.

There are various algorithms to calculate relevancy. Each of these algorithms has different relative weights for common factors like keyword density, links, or metatags. That is why different search engines give different search results pages for the same search string.

Major search engines periodically change algorithms. If you want to keep at the top, adapt your pages to the latest changes. This is one reason (the other is your competitors) to devote permanent efforts to SEO. .

The last step in search engines' activity is retrieving the results. Basically, it is nothing more than simply displaying them in the browser – i.e. the endless pages of search results that are sorted from the most relevant to the least relevant sites.

Differences Between the Major Search Engines

There are many examples of the differences between search engines. For instance, for Yahoo! and MSN, on-page keyword factors are of primary importance, while for Google links are very, very important. Also, for Google sites are like wine – the older, the better, while Yahoo! generally has no expressed preference towards sites and domains with tradition (i.e. older ones). Thus you might need more time till your site gets mature to be admitted to the top in Google, than in Yahoo!.

Last Updated ( Friday, 26 June 2009 )