Skip main navigation

£199.99 £139.99 for one year of Unlimited learning. Offer ends on 28 February 2023 at 23:59 (UTC). T&Cs apply

Find out more

How Search Engines Work

This step segues from the preceding step with the aim to help you understand how to organize your website for optimal SEO performance.
While SEO changes frequently in small ways, its key principles do not. Since Google came onto the scene in the late 1990s, we can break SEO into three components. One, technical optimization. Two, on-page optimization. Three, off-page optimization.
Technical optimization is the process of completing activities on your site that are designed to improve SEO but are not related to content.
On-page optimization is the process of ensuring the content on your site is relevant and provides a great user experience.
Off-page optimization is the process of enhancing your site’s search engine rankings through activities outside of the site. This is largely driven by backlinks, which help to build the site’s reputation. Search Engine Algorithms are computer programs that look for clues to give the searcher the exact results they are looking for. Search engines rely on algorithms to find web pages and decide which ones to rank for any given keyword. There are three steps to how search engines work, crawling, which is the discovery stage, indexing, which is the filing stage, and ranking, which is the retrieval stage. The first step is crawling. Search engines, send out web crawlers to find new pages and record information about them.
We sometimes call these web crawlers ‘spiders’ or ‘robots.’ Their purpose is to discover new web pages that exist and also to periodically check the content on pages they’ve previously visited to see whether they’ve changed or been updated. Search engines crawl web pages by following links they’ve already discovered. So, if you have a blog post and it’s linked from your homepage, when a search engine crawls your homepage, it will then look for another link to follow and may follow the link to your new blog post. The second step is indexing. Indexing is when a search engine decides whether or not it is going to use the content that it has crawled.
If a crawled web page is deemed worthy by a search engine, it will be added to its index. This index is used at the final ranking stage. When a web page or piece of content is indexed, it is filed and stored in a database where it can later be retrieved. Most web pages that offer unique and valuable content are placed into the index. A web page might not be placed in the index if its content is considered duplicate, its content is considered low value or spammy, it couldn’t be crawled, the page or domain lacked inbound links. The third step is really the most important step and that is ranking.
Ranking can only happen after the crawling and indexing steps are complete. So, once a search engine has crawled and indexed your site, your site can be ranked. There are more than 200 ranking signals that search engines use to sort and rank content, and they all fit under the three pillars of SEO, technical optimization, on-page optimization, and off-page optimization. Some examples of signals that search engines use to rank web pages are keyword presence in the title tag, loading speed of the web page, and website reputation.
Google’s main search algorithm is called Google Hummingbird, and it is responsible for deciding how to order and rank search engine results. In 2013, Google upgraded its main algorithm and named it Hummingbird. This upgrade included Google being better able to understand the meaning of keywords and to return more relevant results.
In 2015, Google announced RankBrain, which is a sub-algorithm of Hummingbird and an artificial intelligence system. It processes search results to provide more relevant results for users. This further illustrates the importance of understanding the true meaning of keywords rather than just matching keywords to pages that mention them.

This step segues from the preceding step with the aim to help you understand how to organize your website for optimal SEO performance. It covers the three key components of SEO: technical, on-page, and off-page optimization.


Do you use search engines to help you make a decision. Is it an effective way to get the information you need to help you buy?

Please share your opinion with your fellow learners in the comment section below.

This article is from the free online

Getting Started with Digital Marketing

Created by
FutureLearn - Learning For Life

Our purpose is to transform access to education.

We offer a diverse selection of courses from leading universities and cultural institutions from around the world. These are delivered one step at a time, and are accessible on mobile, tablet and desktop, so you can fit learning around your life.

We believe learning should be an enjoyable, social experience, so our courses offer the opportunity to discuss what you’re learning with others as you go, helping you make fresh discoveries and form new ideas.
You can unlock new opportunities with unlimited access to hundreds of online short courses for a year by subscribing to our Unlimited package. Build your knowledge with top universities and organisations.

Learn more about how FutureLearn is transforming access to education