Introduction to search engine optimization

What is SEO?

This introduction to search engine optimization outlines some basic principles and explains how to improve your web pages' performance.

With billions of web pages out there the vast majority of Internet users have become reliant on search engines such as Google, Yahoo and MSN, to find the information they are looking for. As a result being listed near the top of appropriate searches has become a much-coveted goal for many sites. How do they achieve this? That's where search engine optimization (SEO) comes in.

SEO is the art of building, or tweaking, a web site so that it will be well-placed in search engine rankings for a desired set of key terms. On achieving this a site will also find that it attracts a better quality of visitor — one who is actually interested in the subject matter. It should be noted that SEO primarily concerns itself with organic searches; that is, unpaid search results as opposed to pay-per-click (PPC) advertising.

In this introduction to search engine optimization we will outline some of the basic principles of SEO and explain how they can be used to improve your web pages' performance in search results.

How search engines work

Before we can begin applying SEO techniques to a site we first need to understand how search engines determine what pages to list in their results.

Search engines use automated programs (known as 'bots' or 'spiders') to 'crawl' the pages of the World Wide Web. Once a page has been crawled its contents are stored in the search engine's database, a process known as 'indexing', and can then be found from searches.

When a user performs a search the engine retrieves all the documents that match the search term from its database of indexed pages and orders them so that the pages deemed most relevant appear first.

The key to SEO then, is to design a site so that it is deemed highly relevant for appropriate searches.

Creating relevant content and identifying your key terms

The first part of this process is identifying the key terms to target. These terms should be what you expect your target audience to be entering into a search engine in order to find a site like your own.

Studying the keywords currently being used to find your site can help identify which terms are already working well. There are also key term analysis tools, such as Yahoo's Overture and Wordtracker, that can help identify which key terms are worth pursuing. If you use pay-per-click advertising (such as Google AdWords) you can study your campaigns' performance to see which terms are being frequently used and how your site is rated against them.

Ideally, the terms you choose to target should be frequently searched for but return few other results. More specific terms are often less competitive and bring in visitors with a better idea of what they are looking for. For example, target the term 'women's shoes' and you'll find yourself competing with millions of other web sites; refine your term to 'custom made bridal shoes' and you'll find not only that there are fewer sites competing for the term, but also that the visitors finding your site using this term have a clearer idea of what they are looking for. For an e-commerce site, if a customer can find what they are looking for, they are more likely to buy.

Applying key terms

Having identified the set of key terms that we hope will attract our target audience we can now begin applying SEO techniques in order to improve our ranking. As we do there are a few things that we need to bear in mind.

Firstly: the content is ultimately for visitors; so it needs to be well written. Throwing in a bunch of key terms where they don't belong will actually have a detrimental effect on a page's ranking. Even Google advises you to focus on the users and not the search engines [...] Ask yourself what creates value for your users.

Secondly: your use of key terms should be consistent; using the same terms throughout your content will help to reinforce their importance and subsequently affect how relevant search engines feel the page is.

Page titles & descriptions

The structure of each web page allows you to define a title (which displays on the browser's menu bar) and description (which will not be visible to visitors) within the source of the page. All too often these elements are overlooked and pages will be given short titles such as 'Home' or 'MyCompanyName: Home'.

These elements, however, carry a lot of weight when a search engine comes to rating a page's relevancy. Using your key terms in a page's title and then repeating these in a short description will have a positive effect on your ranking. For example, the home page of Sponge-built has the title 'Buy Interior Doors and Exterior Doors Online'; this helps it sit top in a search for 'interior doors' or 'exterior doors' on and within the first page of results on

In addition, this title and description will be displayed in the list of search results seen by your target audience, so it is important to make a good first impression.


Within the main content of your web page you have the opportunity to give each section a heading (this text is usually larger than other text). Again, search engines treat these headings with great importance and should be populated with key terms, where appropriate.

A common mistake made is to fill a top level heading (the <h1> tag) with the company name. Any content within this heading will be treated as the most important text on the page. Is your company's name really the most important detail on the page? This heading should describe the page, not tell you who it belongs to. Using your key terms, in context, within this heading will do far more for your ranking.

URL design

URLs (a.k.a. web addresses) offer another, often overlooked, opportunity to exploit our key terms. By using key terms within a page's address we yet again reinforce the importance of these terms.

Consider the following sample URLs:

They mean nothing to man or machine (in fact, many search engines won't even bother indexing the first example). These URLs could easily be rewritten to be more meaningful, such as the example below:

From the above URL it's easy to see what the page is about and search engines take this into account when calculating a page's relevancy for search results. As well as being better for search engines, URLs of this design will also be better for your site visitors. Any visitor to this page can easily assume that in order to return to the children's toys main page, they have only to remove the 'baby-elephant...' part of the URL.

Submitting to search engines and providing a sitemap

Applying these techniques will be completely wasted if search engines are not indexing the pages of your site

Of course, applying these techniques to your page will be completely wasted if the search engines' bots are not indexing the pages of your site. To ensure this indexing takes place, you will have to submit your site to the engines. Once you have submitted your site for indexing a search engine will regularly crawl through your site, visiting all your links and indexing them as well.

An excellent way to ensure the pages of your site are indexed is to provide a sitemap. A sitemap is simply a page that links to all other pages on your site that you wish to have indexed. When a search bot reaches a sitemap page, it will follow each of the links on that page and index all the pages of your site.

In addition to a sitemap page, you can also set up an XML feed that will inform the search engines when the links within your site change, so that the site may be re-indexed.

Link-based popularity

While the above sections of this introduction to search engine optimization have discussed how content can improve a page's relevance, there is another key factor that the search engines consider when determining the order of results: popularity.

As well as the information contained within a page, the search engines also pay close attention to what other pages have to say about it. The more sites linking to your page using similar information, the higher the ranking will be for that page.

For example, trying performing a search for the phrase miserable failure on Google and you'll find that George W Bush's biography on the official White House website appears number one in the results! The page certainly does not describe Dubya as a miserable failure, but the number of other websites that link to the biography using the phrase has 'tricked' Google into thinking the phrase is highly relevant to the page.

Using this knowledge, we can better design the links between pages of our own sites. Clickable text should include the key terms for the corresponding page wherever possible, and avoid using terms such as 'click here' which are of no consequence. Where using key terms is not appropriate (e.g. in your main navigation, where you want to keep the links relatively short), it is possible to add a title attribute to the code for the link; these titles will allow you to expand upon the displayed text and can be populated with key terms (in proper context).

Having other reputable sites (the quality of the linking site is an important factor) linking to your own will also have a positive impact on your ranking. In addition, if this link is one-way (i.e. you do not link back to the site that links to yours) it can improve your ranking even more.


Popularity and relevance of content will both effect how highly search engines regard a page

This article has shown some of the techniques that can be used to improve a web site's ranking in the search engines. Popularity and relevance of content will both effect how highly search engines regard a page, and both are within the control of the site's owner, to an extent. Remember also, that this article is merely an introduction to search engine optimization and that there are many other tools and techniques that can be used in addition to ones discussed above.

Search engine optimization will not improve a page's ranking overnight; the process is a long-term strategy and you will need patience in order to be successful. Stick with it though, and SEO can greatly improve your online presence.


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