How do Search Engines work | Digital Marketing Institute

Key Takeaways

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 helped 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 webpages 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 linked from your home page when a search engine crawls your home page 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 optimisation and off page optimisation 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 2000 fifteen 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