2 How does a search engine work?

We all use search engines in our daily routines to find information swiftly, whether it’s for writing a research paper or locating a restaurant in town. A complex web of technology works behind the scenes to make this ability possible.

In this video, you explore how search engines work by diving into the three fundamental tasks of crawling, indexing, and ranking.

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Search engines have become a part of our daily lives, helping us find information from simple facts to detailed research.

They also allow us to stay informed on the latest news, indulge in online shopping, or even help us plan a trip by providing keywords and straightforward queries.

There is a world of information at your fingertips, but what really goes on behind the scenes? It all starts with three fundamental tasks, crawling, indexing and ranking.

Search engines deploy programs known as crawlers or web spiders to find new or updated web pages.

These crawlers explore the web by following links from one page to another, discovering new or updated pages to add to the search index.

The word indexing appears above a file folder and a stack of binders.

The second task is indexing. Once the content is found, it is time for indexing.

Here, the data found is catalogued in a massive database called the search index.

Like a librarian organising books on shelves, the third task is ranking.

When you ask a question, the search engine sifts through the indexed content, prioritising pages to ensure you get the most relevant answers.

This involves complex algorithms that consider factors such as the frequency and location of keywords within the web page, the overall quality of the content and the analysis of the link.

Let's put this into perspective. Say you are searching for Italian restaurants in your city.

The search engine springs into action, suggesting a list of websites.

This selection is not random, it is the results of precise ranking, where each page's relevance is assessed based on your search. From the moment you type in your query to how quickly the results appear, you are seeing the seamless dance of crawling, indexing and ranking.

It is a journey that brings knowledge to your fingertips, all in the blink of an eye.

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Search engines evolved to help you receive the most accurate and updated information. They begin by crawling and indexing websites. That is, they scan the web and record the content that they discover. They then use this extensive database to rank and fetch the results for your queries.

The algorithms that drive these activities are highly advanced. They’re crafted to comprehend the context and purpose behind your searches.