What is SEO

when ever   you enter a query in a search engine and hit 'enter' you get a list of web results that contain that query term. Users normally tend to visit websites that are at the top of this list as they perceive those to be more relevant to the query. If you have ever wondered why some of these websites rank better than the others then you must know that it is because of a powerful web marketing technique called Search Engine Optimization (SEO).

SEO is a technique which helps search engines find and rank your site higher than the millions of other sites in response to a search query. SEO thus helps you get traffic from search engines.

This SEO tutorial covers all the necessary information you need to know about Search Engine Optimization - what is it, how does it work and differences in the ranking criteria of major search engines.

How Search Engines Work

First, search engines crawl the Web to see what is there. This task is performed by a 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 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 may not end up visiting your site for a month or two.The first basic truth you need to know to learn 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 –crawling, indexing, processing, calculating relevancy, and retrieving.

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 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 with 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, Bing, 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.

Differences Between the Major Search Engines

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!.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.

What is SEM

What is search engine marketing (SEM)? What is search engine optimisation (SEO)? How do I promote my website? Do I have to outsource to a consultant or is that going to harm my site since they're all spammers anyway?

There is a lot of helpful information, as well as a lot of misinformation, floating around regarding search engine optimisation (SEO) and search engine marketing (SEM). First of all, let's start with the names: SEO stands for search engine optimisation (or optimization if you're from the States). In its simplest form SEO is the process of tailoring a website (text, titles, meta tags, alt tags, etc) so that the search engines will assign a good rank to the site for specific search terms.

But with the advent of search engines introducing fees for guaranteed inclusion in their indices, directories charging for reviews and the emergence of PPC listings, SEO now has an element of media buying mixed in. Thus, thanks to Danny Sullivan, it has now been called search engine marketing or SEM (you can still call it SEO if you want).

The SEM Guide is meant to be both a tutorial and a general information resource. I am not selling or promoting anything (other than best practices). I have done SEO / SEM for 5 years and started this site as a way to organise my bookmarks and the information I had collected over the years. If you frequent other prominent SEM resources you'll find that this tutorial, like most search engine promotion sites, tends to go over the same ground. This is because THERE ARE NO SECRETS to successful search engine positioning - just experience, a lot of research and tons of hard work.

If you don't have the time to do it yourself get some expert help. But if you want to try your hand at promoting your own web site or you just want a better insight into how it should be done take the search engine marketing tutorial by following the steps.

The SEM Guide covers other subjects that are not included in the step-by-step tutorial so be sure to check out the side and top menus where every page of the site is listed. Now, on with the search engine marketing tutorial: