This is Tutorial 2 of 12 in the SEO Basics for Beginners series. In Tutorial 1, you learned what SEO, AEO, and GEO mean and why they matter. In this tutorial, we will go deeper into search engine crawling, along with indexing and ranking, the three steps every search engine follows before showing results to a user.
Once you understand this process, the rest of SEO will make a lot more sense, because almost every SEO technique exists to help your website perform better in one of these three steps.
The Three Steps: Crawling, Indexing, Ranking
Search engines like Google do not magically know about your website the moment you publish it. They follow a clear process made of three stages. First comes search engine crawling, where bots discover your pages. Second comes indexing, where the discovered content is stored. Third comes ranking, where pages are ordered based on relevance and quality.
| Step | What Happens |
|---|---|
| Crawling | Bots visit your website and read its pages and links |
| Indexing | Your page’s content is stored in the search engine’s database |
| Ranking | Pages are ordered for a search query based on relevance and quality |
What Is Search Engine Crawling?
Search engine crawling is the process where automated programs, called crawlers, spiders, or bots, visit websites across the internet and read their content. Google’s main bot is called Googlebot. It moves from page to page by following links, much like a person clicking from one webpage to another.
When search engine crawling happens on your website, the bot looks at your text, images, links, and code structure. It also checks a special file called robots.txt, which tells bots which pages they are allowed or not allowed to visit.
User-agent: *
Disallow: /admin/
Allow: /The example above is a simple robots.txt file. It tells every bot (“User-agent: *”) that the “/admin/” folder should not be crawled, while everything else on the site is open to be crawled.
Why Search Engine Crawling Sometimes Fails
Sometimes a bot cannot complete this process properly, and your pages never get indexed. This usually happens for a few common reasons, listed below:
- The page is blocked in robots.txt by mistake
- There are no internal links pointing to that page
- The website loads too slowly for the bot to finish scanning
- The page has a “noindex” tag added by accident
- The website is brand new and has not been discovered yet
As a beginner, one of the easiest habits to build is submitting your sitemap to Google Search Console. This gives bots a clear map of every page on your site, which makes crawling and indexing much faster and more reliable.
From Indexing to Ranking
Once a page is successfully crawled, it moves into Google’s index, a massive database of billions of pages. When someone types a search query, Google does not crawl the web instantly. Instead, it searches through its already-built index and ranks the most relevant, trustworthy pages at the top.
Ranking depends on hundreds of factors, including keywords, page speed, mobile-friendliness, and the quality of content. We will cover many of these ranking factors in later tutorials, especially when we discuss On-Page SEO and Technical SEO.
How AI Answer Tools Find Content
In Tutorial 1, you met AEO and GEO. These work on top of the same process you just learned. AI tools like ChatGPT, Google AI Overviews, and voice assistants also need to find your page first, which means your content must be open to bots and easy to read before any AI tool can use it.
In simple words, if a bot cannot reach your page, an AI tool usually cannot use it either. That is why a clean, crawlable website is the base for SEO, AEO, and GEO. We will study how to write content that AI tools like to pick in Tutorials 10 and 11.
Checking If Your Page Is Indexed
You can quickly check whether Google has indexed your page by typing site:yourwebsite.com directly into the Google search bar. If your page appears in the results, it means search engine crawling and indexing were both successful for that page.
For a deeper technical explanation, Google’s own How Search Works documentation covers crawling and indexing directly from Google’s engineering team.
Practice Exercise
Complete the following tasks to practice what you learned in this tutorial:
- Open your own website (or any website) and search for its robots.txt file at yourwebsite.com/robots.txt
- Write down what the robots.txt file allows and disallows
- Use the site: search operator to check if a page from your website is indexed
- List the three steps of crawling, indexing, and ranking in your own words
- Name two reasons why search engine crawling might fail on a website
- Check if your website has a sitemap.xml file, and write down its URL
- Write one sentence explaining why a blocked page cannot be used by AI answer tools
Bonus Challenge: If you have access to Google Search Console for any website, submit its sitemap and check the “Coverage” or “Pages” report to see how many pages have been crawled and indexed so far.
In the next tutorial, we will explore the different types of SEO, including On-Page, Off-Page, and Technical SEO, and how each one supports crawling, indexing, and ranking in its own way. Visit our SEO category page to see all tutorials in this series.
