Google is as fast as it is? When you enter a
search query in Google Search, you see the
time taken to return your results, and that time isn’t
even measured in seconds, but rather, milliseconds.
How can it be so fast? Searching for a file on your
computer or a local area network can take minutes.
Surely, the internet can not be faster than your own
computer’s storage? That’s a really good question which
I am sure some of us have pondered over at one time or another.
So what actually is going on?
o understand the answer to the question, you must first get
a very basic idea of how search engines actually work. At its
core, a search engine consists of a crawler and an indexer
(let’s leave the headache ranking pages for now, shall we?)
The crawler’s job is to crawl the web, and I mean literally!
It crawls from one page to another through hyperlinks. That
is why if you build a new website, building links to it from
other sites is a quicker way of getting it noticed than submitting
it to Google’s index. The crawler reaches into every accessible corner
of a website (if it is linked from another page).
Once the crawler has found a page, it is the indexer’s job to index the
page’s content. Indexing means processing and parsing the data on the
page, and then saving it in a statistical, more meaningful form, something
which the search engine can understand easily. This data is saved on the
search provider’s web server.
So once a crawler finds a page, the indexer processes it and stores it on a
server. The search engine now has nothing more to do with the page in question,
unless it wants to re-crawl and re-index that page (in case of updates. Google
indexes webpages every second or every day, depending upon the ranking of the website).
Now, when a user requests a query, the search engine doesn’t actually search the web.
It has already done that! It simply searches from the index found on
its own servers, and returns relevant results.