Search Engines Works by crawling billions of pages on the internet using web crawlers also known as bots or spiders. These bots navigate the web regularly to find recent and pages to add to search engine index.
So When you type a query into a search engine like Google or Bing, web crawlers crawl hundreds of billions of pages in their index, choose which are most relevant (based on many factors), and serve you an answer.
In this guide, we will provide you with a basic understanding of how search engines work through these three steps: Crawling, Indexing and Ranking
What is Search Engine?
Search engines (like Google, Bing, Yahoo, DuckDuckGo, Yandex and Baidu) are searchable databases of web content. It is made up of search index and search algorithm(s)
1. Search index is a digital library of information about webpages.
2. Algorithm(s) is/are computer program(s) that is tasked with matching your search queries with results from the index.
What is The Aim of Search Engines?
The primary aim of a search engine is to deliver the most relevant, high-quality, and accurate results to a user’s query as quickly as possible
Its core goals are to
- Catalog and structure the vast amount of data available on the internet into a searchable index.
- Understand what a user is looking for by analyzing their keywords or questions
- Rank trustworthy, useful, and authoritative content above low-quality pages
- Provide fast, efficient access to information so users do not have to browse multiple websites manually.
Organize Information âž” Match Intent âž” Prioritize Quality âž” Save Time
How does a Search Engine Work?
Search engine works in three stages:
- Crawling
- Indexing
- Ranking (Serving search results)
1. Crawling: Finding Site and Content on the Web
Crawling is a process by which search engines find what exists on the web.
For search engines to serve you web pages they must discover them first. This process is called “URL discovery”. Search engines finds pages by either following the link from a page that’s already found or reading the sitemap. When they discover a page’s URL, they send crawlers (also known as robot, bot, or spider) to visit the page to know what’s on the page. Simply put, The bots look at them and analyzes the written content, non-written content, visual appearance, and overall layout.
Crawlers basically uses an algorithmic process to determine which sites to crawl, how often they crawl it, and how many pages to fetch from each site. This process can range between few hours to few days or even weeks. Factors such as popularity, seasonality, and structure, all play a role in how often your site is crawled.
However, it is important to note that bots do not crawl all the pages it discovers; reason being that Some pages may be disallowed for crawling by the site owner, other pages may not be accessible without logging in to the site.
2. Indexing: How Search Engines Adds and Stores Content to Search Database
Indexing is the process of analyzing, storing and cataloging a crawled page. Note: Not because a page is crawled would make the page indexed – The information on the page must be relevant.
After a page is crawled, search engines tries to understand what the page is about by analyzing the textual content (like the keywords used on the page) tags and attributes like the title of the page, images, videos, alt attributes and more.
During the indexing process, search engine like Google first determines if a page is a duplicate of another page on the internet or canonical. To do this, google gathers all the pages on the internet with similar content then select the one that is most representative of the group to display on the first page of search engine result page (SERP). The other pages in the group are considered alternate versions. they may be served in different contexts, like searches from a mobile device or users looking for a very specific page.
3. Ranking: Serving Search Results
Once pages are crawled and indexed, they are eligible to be served in a search engines results page (SERP). At this stage, when a user enters a query, search engine searches the index for matching pages and return the results with highest quality and most relevant to the user’s query. The relevancy of a page is determined by lots of factors like: location, language and device(desktop or mobile phone) search intent of the user. Meaning when a user searches for “travelling bag stores”, the result would be different across different location and devices. And base of the query, “travelling bag store” will likely show physical store location near you. However, just searching for “travelling bag” will most likely show images.
It is important to note that certain pages won’t be seen even though search console tells you that a page is indexed. this is because Search engines determine rankings by many factors. Decoding ranking factors and determining which your website needs to improve is the basis of search engine optimization (SEO).
Final Thought
Understanding how search engine works is crucial for optimizing your website and gaining visibility. Remember, search engines aim to provide users with the most relevant and high-quality results, so aligning your content and strategies with these goals will ensure better performance.
By focusing on good keyword optimization, content relevance, freshness and mobile friendliness, your site will rank and drive traffic.
