SEO glossary – crawling, indexing and ranking

The end goal of SEO is to appear on search engines and in time rank higher in their results pages in order to attract new customers and reach existing ones. For your content to be visible and ranked on search engine results pages (SERPs), it needs to be found by search engines. They (search engines) find information using three main methods – crawling, indexing and ranking.


As the name suggests, this is how search engines go over the code or content of each URL they find to discover new content. They do this by sending out robots/bots known as crawlers or spiders to find new or updated content in any form. Whether it is a PDF, an image, webpage, etc as long as it is in the form of a link, it can be found by the crawlers.

How it works

Crawlers will start by fetching webpages and will then follow the links on those webpages to find new content and URLs. The content is then added to a massive database to be retrieved when someone is searching for information. If the content on that URL is good quality and relevant to their search query, it will be shown to them.


This is like a library, where information is grouped and stored according to preset criteria.

How it works 

Content discovered by the crawlers is stored and organised by indexing. Once a URL has been indexed, it’s in the running to be displayed as a search result to relevant queries. 


Again, as the name suggests, this the way search engines sort content and URLs in order from most to least relevant.

How it works

When someone enters a search query, search engines will go through their index for the most relevant content to present to the searcher. The higher a result is ranked, the more relevant it is to the search query – according to the search engine.

Hopefully, this glossary was able to make things clearer regarding these 3 main frequently used SEO terms. Feel free to follow us on Facebook, Instagram, Twitter or LinkedIn to stay up to date and know when we publish new articles. For any business-related queries kindly email us on