How Search Engines Operate

Essentially Search Engines like Google have two primary functions. These two key functions are Crawling and Index Building. What we as users see, is a ranked list of websites, the search engine has determined as most relevant based on our search query.

Search engines

If you think of the World Wide Web as an underground or subway system in a big city, each stop within the system would be considered as a web page.

Search Engines need to find the best route to “crawl” the entire system, finding all the best and most relevant stops along the way.

The Search Engine uses “links” to achieve this.

Link Structure

Simple key for some of Google’s important terminology

Links form the base of how all searches are made on search engines. They allow billions of documents across the web to be accessed by Bots and Spiders, which crawl the documents.

Massive databased then store selected pieces of content and documents, once the code has been interpreted. These databases then allow pieces of content to be accessed when a search query made.

Search Engines like Google have built city sized datacentres all over the world, which not only store billions of documents added to their databases but also allow information and content to be accessed instantly when a user makes a search. It really is a technical marvel.

Search Engines are extremely intelligent. When a user submits a search, the engine sifts through billions of documents and files performing two key tasks:

  • The search engine returns results that are that relevant and useful to the search query submitted
  • The results are ranked according to the popularity of the website result

And this brings us onto the next major function of search results and a key principle of SEO influence.



A fundamental question, constantly asked is; “How do search engines use relevancy and popularity in their listing of search results?”

Search Engines generally assume that the more popular a piece of content, a website or a document, the more important and more relevant the information is to the user entering search queries. This is where the Engines algorithm, which is essentially a series of complex mathematical equations, comes to action.

The algorithm will filter through billions of documents and pieces of content, and offer the most RELEVANT results based on your search query. It will then rank those results in your results listings by POPULARITY. All of this is done in a fraction of a second. Hundreds of variables are considered in the ranking of websites in search results listing. These “Ranking Factors” form a fundamental role in Search Marketing activities.


  1. User centric pages as opposed to search engine centric pages will achieve better results
  2. Do not deceive your users or present different content to users and search engines. It’s a technique called “cloaking” which can damage rankings
  3. Usability and hierarchy are important. Every page should be reachable from at least one link
  4. Content and information rich web pages with descriptive ALT and <title> elements will achieve higher levels of relevance and in turn, popularity
  5. Anchors (URL’s), should be created using keywords in a friendly, human manor