1. Could you please explain the process of how search engine works

A search engine works through several complex processes, but the basic process can be understood through three main stages:

Crawling → Indexing → Ranking

To understand this easily, let us take a simple example of Lulu Mall.

1. Crawling – Discovering the Products

Imagine that you enter Lulu Mall because you want to buy something.

Inside the mall, there are different sections and racks. One rack may contain perfumes, another may have pens, another may contain vegetables, and another may have fruits.

If you are looking for a good perfume, you will go to the perfume section and explore the available products.

Similarly, search engines continuously discover webpages across the internet. Search engine crawlers, also called bots or spiders, visit websites and follow links to discover new pages and pages that have been updated.

This process is called Crawling.

In simple words:

Crawling = Discovering and accessing webpages on the internet.

For example, if a website publishes a new article about “Digital Marketing Strategies,” a search engine crawler may discover that page through links, XML sitemaps, or other signals and access the page to understand its content.

However, crawling does not mean that Google has decided that the page is good or that it will rank highly. It simply means that the search engine has discovered and accessed the page.

2. Indexing – Understanding and Organizing Information

Now imagine that you have explored the products inside Lulu Mall.

You identify the products, understand what they are, and decide which products you may need. You then purchase some of them and take them home.

You organize the products in your refrigerator so that you can easily find them whenever you need them.

Search engines work in a similar way.

After crawling a webpage, the search engine analyzes and understands its content. It may process information such as text, images, videos, links, structured data, and other information associated with the page.

If the page is eligible for indexing, information about that page is stored and organized in the search engine's Search Index.

This process is called Indexing.

We can compare the Search Index to your refrigerator.

Once you have bought apples, oranges, and vegetables from Lulu Mall and kept them in your refrigerator, you don't need to go back to Lulu Mall every time you need an apple. You can simply open your refrigerator and take one.

Similarly, search engines use their Search Index to quickly find information about webpages when a user performs a search.

So:

Indexing = Analyzing, organizing, and storing information about webpages in the search engine's index.

Important: We should not say that Google simply downloads and stores a complete copy of every website's files on its servers. A more accurate explanation is that Google processes and stores information about webpages in its Search Index.

3. Ranking – Selecting the Most Relevant Results

Now suppose you want to buy tomatoes from Lulu Mall.

There may be many tomatoes available. You will compare them based on factors such as freshness, quality, appearance, price, and your personal requirements.

You will then choose the product that best matches your needs.

Search engines work in a similar way when you perform a search.

For example, suppose you search for:

“Best Digital Marketing Course in Trivandrum”

There may be hundreds or thousands of webpages related to digital marketing courses.

The search engine needs to determine which results are most relevant and useful for your particular search.

It uses many signals and systems to determine how relevant and useful a result may be for the query.

This process is called Ranking.

In simple words:

Ranking = Determining the order in which relevant search results are presented to the user.

The Complete Process

We can understand the complete search engine process using our Lulu Mall example:

Step 1: Crawling

You enter Lulu Mall and explore different sections and racks to discover what products are available.

Search Engine: Crawls the web and discovers webpages.

Step 2: Indexing

You understand and organize the products you have purchased and keep them at home for future use.

Search Engine: Analyzes and organizes information about webpages in its Search Index.

Step 3: Ranking

When you need something, you select the product that best matches your requirements.

Search Engine: When a user searches, it determines which relevant results should appear and in what order.

Step 4: Search Results

You finally choose the product you want.

Search Engine: It displays a Search Engine Results Page (SERP) containing relevant results and, depending on the query, other search features such as images, videos, maps, featured information, or other result types.

An Easy Way to Remember

You can remember how a search engine works with three simple words:

Crawl → Index → Rank

Crawling:
“Where are the webpages?”

Indexing:
“What is each webpage about?”

Ranking:
“Which relevant results should I show for this search?”

So, when you search on Google, the search engine is not manually checking the entire internet at that exact moment. Search engines have already discovered and processed huge amounts of information and organized it in their Search Index.

When you perform a search, the search engine uses that index and its ranking systems to identify relevant results and present them in an appropriate order.

In short:

Crawling discovers webpages.
Indexing processes and organizes information about those webpages.
Ranking determines the order of relevant results for a user's search.

This is the basic process of how a search engine works.