How Search Engines Actually Work: A Step-by-Step Guide

You Type Three Words. Millions of Answers Show Up. How?

If you type “best pizza near me” in Google, there it is – instant results. You won’t even notice that. What happens, however, when you put the words in the search bar? Well, some sort of a crazy thing starts taking place somewhere. A machine somewhere goes through billions of pages, ranks them, chooses the best ones for you. It’s not random, it’s not magic – there is an entire system, developed over decades and ever-changing behind the scenes. Understanding how it works will change your perspective on the search bar forever.

Step One — Crawling: The Internet's Never-Ending Road Trip

Visualize Internet as one big city. Every second new buildings are coming up, some of the existing ones are getting renovated and some of them are demolished. Now visualize a delivery man whose job is only to travel across all the streets in the city, write all the addresses and figure out what all are there in these buildings. This is what the crawlers do. These tiny little programs which are also known as bots or spiders are used by the search engines which visit every single website through links.

However, here’s the catch: crawlers do not see everything immediately. Freshly launched sites may be discovered in days or weeks. Pages that require login access are typically never crawled by the search engine. That’s why sometimes certain pages are indexed quickly, while others are taking ages or are not indexed at all. Website administrators can also ask the search engine to index the page or not, thanks to the little-known yet extremely powerful robots.txt file, which is just like hanging a “delivery accepted” or “no deliveries allowed” note on your door.

Step Two — Indexing: Building the World's Biggest Library Card Catalog

So the crawler had a copy of the page. And then? Well, here is where indexing comes into play, and this is where most people get surprised by what search engines do. Search engines don't store all pages in one heap. They index them, acting in some way like librarians, reading all the books they have and creating a card for each one of them. What does the book talk about? What words does it use more often? Is it a recipe, a news item, or maybe an offer of something to buy? As soon as this card is created, it is filed in a system so huge that it is unimaginable. Hundreds of billions of pages are in this index. But not unstructured and unordered files – something a computer can instantly find.

Consider the case of a library. Suppose there is no system by which the books can be classified and sorted according to the topics. You will have to spend a considerable amount of time searching for the required information. But when books are sorted according to their subject matter, author, and title, you can easily find exactly what you require in just a few minutes. The same is the case with search engines that work on the same basis as they sort each and every page according to the key words, topics, and even meanings of sentences.

• Crawlers scan the web nonstop, following links

• Indexing organizes pages like a giant digital library

• Robots.txt tells crawlers where they can and can't go

• Search engines understand meaning, not just exact words

• Pages behind logins usually don't get indexed

• New sites can take time before showing up in results

Step Three — Ranking: Why Some Pages Win and Others Get Buried

And now we've reached the good part. Crawling and indexing is just the first step to being successful online. Getting on the first page of results is a whole different ballgame. There are complicated algorithms in which hundreds of different factors come into play. Is the information relevant? How fast is the page loaded? Are there any links from reputable sources to the page? Is the page mobile-friendly? Does the page actually solve the problem that you are asking about or avoids answering it altogether? None of these measures can work alone; they are all combined and recombined all the time to generate new results.

The concept of backlinks becomes very important here, and there is a lot of misconception concerning it. Backlink is another website saying good things about yours. Ten random blogs linking to your article is okay, but one major and trusted website making a backlink to you means much more. In other words, backlinks can be considered a sort of recommendations. An opinion of an absolute stranger counts, but the opinion of an established authority counts much more. The search engine also analyzes user behavior. If people open a link and return to the search right away, this particular webpage does not provide an adequate answer to the user's question.

Why Search Results Feel Personal (Because They Kind Of Are)

Have you ever realized that the results retrieved in response to your query are always different from those that your friend gets when they use the same search engine and key in the same search term? This is by design because the search engines rely on your location, past searches, the device that you are using for searching, and in some cases, even the time of the day as part of their algorithm. Whenever you search for something like "restaurants open now," you are supposed to get different results depending on where you are located. In case you search for "football," your results will differ from those of someone in Britain.

What does this say about people who do not spend time optimizing their SEOs? It says that content should be written to be useful, not keyworded. It says that fast-loading pages which are also mobile-friendly have an advantage over those which are not. It says that trust is more important than manipulation. Search engines can now recognize manipulations and penalize them. Sites that make it through in the end are the ones who help people, not the ones who exploit algorithms of search engines.