How Does Google Work?   by Richard Crawford

in Website Promotion / Online Promotion    (submitted 2011-09-06)

Clients often ask me what rules search engines use to rank their website. In order to explain, it's best to start at the beginning:

What exactly is a search engine, anyway?

One of the fantastic things about the net is that, for any given topic you could possibly think of, there are literally millions of pages of information. One of the worst things about the net is that there are literally millions of pages of...

See where I'm going with this?

A search engine is basically a website that's designed specifically to help people find information stored on other websites. People too often use the term 'search engine' to describe both spider or crawler-based engines (such as Google or Bing), as well as human-powered directories. These two types of engines actually get their results in starkly different ways. For the purpose of this article, however, I'm going to talk just about spider/crawler-based engines, such as Google.

They all work in different ways, but they do all have the following common features:
1. They crawl the net based on keywords that are deemed important
2. They maintain an index of these terms, and where they occur.
3. They let you, the user, look for keywords or keyphrases found in that index.

As they crawl the web, engines use small programs called 'spiders', that are constantly browsing the Internet. Another program provides the URLs that the spiders need to scan.

For the indexing process, a copy (or cached version) of the pages that spider found are saved. From this cache, a record of the words from each page, as well as the URLs where this word has been found, is saved in a huge table.

When a user searches for a given keyword or term, they see the most relevant results for that particular search. These results are ordered according to ranking criteria, which is determined using different algorithms or formulas for each engine, in order to determine relevance.

Although these algorithms are kept very secret by the various engines, the frequency of a particular keyword or phrase's appearance in the body text of your site is one of the main factors in calculating your page's relevance to those terms. Search engines list the most relevant results first. Some other factors that they determine rankings with are internal linking, description metatags, incoming links from other sites, use of bold text, and page titles.

Which is better? Organic results, or Paid results?

The biggest engines like Google, Yahoo or Bing deliver results for your search query in two different ways - Organic results, and Paid results. The organic results for a given search are the result of the process outlined above.

Paid results, however, is a model used by search engines that allows site owners to pay the search engine to guarantee their website will appear in search results. Also, this paid including might even influence the spiders or crawlers to visit the site more frequently, and may give the owner the option to submit their information about the page more often. They all treat these paid results in different ways. Some call these results advertisements, whereas others might describe them as simply other results alongside organic search results.

What exactly is SEM?
SEM stands for Search Engine Marketing. This is the process of designing a website with the intention of specifically increasing the site's ranking in the search results. Most of the time, the term SEM means the paid methods of doing this, such as PPC (pay per click), banner ads, PPI (pay per inclusion) and various other paid methods.

And what's SEO?
SEO stands for Search Engine Optimisation. This is different to SEM in that is refers to the process of building a site or writing copy so that it ranks higher in the non-paid, organic results. This might involve the following techniques:
• writing body text with SEO in mind
• titles and meta tags
• removing flash content and crawler-unfriendly material
• making internal links, incoming links, and exchanging links with related and reputable web sites
• URL optimisation
• directory structure optimisation
• site maps, and a crawler-friendly 404 page

About the Author

Richard Crawford is a web designer who really knows his stuff.

Find out how Rick can show you how Google works, or what search engines are.