Search Engines: what are they and how do they work?

Search engines allow users to search the internet for content using keywords. Although dominated by a few, there are several search engines that people can use. When a user enters a keyword or key phrase into a search engine, a search engine results page (SERP) is returned, ranking the found pages in order of their relevance. How this ranking is done differs across search engines.

They often change their algorithms (the programs that rank the results) to improve user experience. They aim to understand how users search and give them the best answer to their query. This means giving priority to the highest quality and most relevant pages.

How do search engines work?

They use programs, often referred to as spiders, robots or crawlers, to search the internet. These programs are used by search engines to build an index of the internet. However, although most search engines will provide tips on how to improve your page ranking, the exact algorithms used are well guarded and change frequently to avoid misuse. But by following a few well accepted search engine optimization (SEO) techniques you can ensure that your website is well indexed and remains high in the rankings.

Different search engine methods

Each of the three main engines use different methods to rank websites. Understanding these methods will help you understand the SEO strategies outlined in this guide.

The three main search engines are:

Google – Google assesses the value of a web page based on the number of back links ie links back to your website. Links from pages that are seen as important by Google weigh more heavily and increase the ranking of the linked pages. Google also analyses the relevancy of the content on the page and other factors like mobile-friendliness. The Google ranking algorithm changes constantly. It can be useful to keep up to date with the latest changes.

Yahoo! – Yahoo! began as a manually edited directory. It now uses link analysis tools to determine page relevancy, though content is also important in deciding search relevance. Other factors that are important include back links and a good site design.

Bing – Microsoft’s Bing search engine ranks websites based on the web page content, the number and quality of websites that link to your pages, and the relevance of your website’s content to keywords.

For more detailed information on how to best optimize your website for a particular search engine, refer to their webmaster pages. All the leading search engines provide information and tools to help you improve your SEO.

There are a number of specialist search engines that allow users to search for specific things like videos, used cars, recipes, flights and hotels. SEO tactics can be used to help your products and services rank well on specialist search engines.