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How do Search Engines Work?
Search engines perform critical operations that allows them to provide relevant web results when searchers use their system to find information.
There are some basic differences in the ways various search engines work, but they all perform four basic tasks:
- Crawling the web
A web crawler, also known as a spider or robot, is an automated program which browses the internet in a constant specific, automated manner.
- Indexing web pages and documents
After a page has been crawled, it's content can be "indexed" - saved in a database of documents that makes up a search engine's "index".
- Processing queries
When a request for information comes into the search engine, it retrieves from its index all the documents that matches the query.
- Ranking results
Once the search engine has determined which of the results are a match for the requested query, the engine's algorithm runs calculations on each of the results to determine which is most relevant to the given query. The search engine’s ranking system lists these results ordered from most relevant to least.
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