The web is made up of over 30 trillion individual pages which is constantly growing. Then how the search engine gives you the exact results for your queries?

It's actually quite amazing

Search engines (Google, Yahoo, Bing, etc) use a "Spider" or "Bot" to search the web for content to present to their users

Important Terms:

        1. Crawling - Visiting the website

        2. Indexing - Collecting database

        3. Cache - Kept the information (storing)

How to check whether the site is indexed or not? Use the following techniques:

       1. site: - No.of links crawled

       2. cache: - Last cache details (or) Use

       3. info: - No.of indexed pages