An Introduction to Search Engines: How Crawling, Indexing, and Ranking Actually Work
You probably want more traffic. You also probably know that one of the best ways of getting more traffic is by increasing your visibility in search.
I bet you don't know though, how exactly to do that OR how these search engines even work.
So, let us pop open the hood and take a look inside.
How do search engines work under-the-hood?
Google, Bing, DuckDuckGo and many other search engines all do pretty much the same thing.
And we can boil it down to three key tasks:
Crawling: Basically a bot visits a website and reads its content. It finds out what the page is about and what other pages it links to.
Indexing: After crawling a page and figuring out what it's about, that page will be indexed. This means it's in the search engine's giant catalog of URLs and can now show your URL if it thinks your content is a good match for something a person is searching for.
Ranking: There are a lot of websites on the internet. Over a billion. One of the most important responsibilities of a search engine is to display the most helpful and relevant results given the search query. So, every search engine has their own ranking algorithms that figure out based on a huge number of factors just how relevant and helpful your site's content actually is.
Let's dive deeper into each of these tasks.
How does search engine crawling work?
In order to display your website in search results, a search engine needs to know your site exists. Crawling is a strategy where a bot scans a website, interprets its content, and looks for other links to other pages. If another site links to your site, a crawler may discover that link and crawl your site next.
These bots, also called crawlers or spiders, are responsible for reading, discovering, and overall keeping up with everything changing on the internet.
It's our job to understand how they work and to create websites that give these crawlers all of the information they need.
What is search engine indexing?
You can think of the search engine index as a database. When we enter a query in a search engine, it gets us the most relevant results quickly. The only way it can do this is by keeping results organized and storing them before hand.
Indexing is the act of adding our website's pages to this database of search results. It's the actual mechanism that lets us show up in search results.
How do search engines determine ranking?
The last part of the puzzle drives how search results are returned. When we search for something, we want high-quality results that are relevant to our search intent. Search engines optimize for this and determine the content to show you by using a series of algorithms.
Expect the quality of your content, the authority of your website and brand, and even the performance and user experience of your website, to have a significant impact on how you rank in search results.
How to Make Sure Your Website Gets Indexed
First, we need to understand every search engine is different. Each applies their own ranking algorithms and has slight variations in how their crawling and indexing strategies work.
But when it comes to the search engine people use the most, Google has the vast majority of the market share. There are more than 30 major search engines around today, but still most SEO experts will focus on Google. It's where more than 90% of searches happen and almost 20x as much volume as Yahoo and Bing get, combined.
However, there are a number of best practices and warnings I can give you to make sure your website gets indexed on all of the major search engines.
Manually Add Your Website to the Index
You don't have to rely on backlinks and crawlers for your website to get indexed by search engines. You can submit your website directly and get it indexed without playing the lottery. Check out Google Search Console to manually add your website to the index. It's also a great tool to manage your search presence and track your search performance, ranking, and organic traffic.
Make Sure Search Engines Can Crawl Your Pages
Even if we submit out website to the index manually, it's important that our website can still be crawled. What will happen is a crawler will be sent to the URL you manually submitted to read the content on your page. If the crawler isn't able to do this, your site won't show up in search results.
Even with manually submitting you website to the index, having a website that can be easily crawled is a clear prerequisite to getting shown in search results.