Search Engine Optimization (SEO) is often considered the more technical part of Web marketing. This is true because SEO does help in the promotion of sites and at the same time it requires some technical knowledge – at least familiarity with basic HTML. SEO is sometimes also called SEO copyrighting because most of the techniques that are used to promote sites in search engines deal with text. Generally, SEO can be defined as the activity of optimizing Web pages or whole sites in order to make them more search engine-friendly, thus getting higher positions in search results.

One of the basic truths in SEO is that even if you do all the things that are necessary to do, this does not automatically guarantee you top ratings but if you neglect basic rules, this certainly will not go unnoticed. Also, if you set realistic goals – i.e to get into the top 30 results in Google for a particular keyword, rather than be the number one for 10 keywords in 5 search engines, you will feel happier and more satisfied with your results.

Although SEO helps to increase the traffic to one’s site, SEO is not advertising. Of course, 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.

SEO can be a 30-minute job or a permanent activity. Sometimes it is enough to do some generic SEO in order to get high in search engines – for instance, 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, if you really want to be at the top, you need to pay special attention to SEO and devote significant amounts of 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.

1. How Search Engines Work

The first basic truth you need to learn about SEO is that search engines are not humans. While this might be obvious for everybody, the differences between how humans and search engines view web pages aren’t. Unlike humans, search engines are text-driven. Although technology advances rapidly, search engines are far from intelligent creatures that can feel the beauty of a cool design or enjoy the sounds and movement in movies. Instead, search engines crawl the Web, looking at particular site items (mainly text) to get an idea what a site is about. This brief explanation is not the most precise because as we will see next, search engines perform several activities in order to deliver search results – crawlingindexingprocessingcalculating relevancy, and retrieving.

First, search engines crawl the Web to see what is there. This task is performed by e piece of software, called acrawler or a spider (or Googlebot, as is the case with Google). Spiders follow links from one page to another and index everything they find on their way. Having in mind the number of pages on the Web (over 20 billion), 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.

What you can do is to check what a crawler sees from your site. As already mentioned, crawlers are not humans and they do not see images, Flash movies, JavaScript, frames, password-protected pages and directories, so if you have tons of these on your site, you’d better run the Spider Simulator below to see if these goodies are viewable by the spider. If they are not viewable, they will not be spidered, not indexed, not processed, etc. – in a word 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, from where it can later be retrieved. Essentially, the process of indexing is identifying the words and expressions that best describe the page and assigning the page to particular keywords. For a human it will not be possible to process such amounts of information but generally search engines deal just fine with this task. 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 pages (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. What is more, it is a known fact that all major search engines, like Yahoo!, Google, MSN, etc. periodically change their algorithms and if you want to keep at the top, you also need to adapt your pages to the latest changes. This is one reason (the other is your competitors) to devote permanent efforts to SEO, if you’d like to be at the top.

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.

2. Differences Between the Major Search Engines

Although the basic principle of operation of all search engines is the same, the minor differences between them lead to major changes in results relevancy. For different search engines different factors are important. There were times, when SEO experts joked that the algorithms of Bing are intentionally made just the opposite of those of Google. While this might have a grain of truth, it is a matter a fact that the major search engines like different stuff and if you plan to conquer more than one of them, you need to optimize carefully.

There are many examples of the differences between search engines. For instance, for Yahoo! and Bing, 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!.