As large as Google has grown, the main motive is to help users find what they want on the internet. And that’s where google’s search engine shines. The Google search engine is one of the powerful tool. Initially Google can help narrow down what you’re looking for with specialized searches (i.e) You can browse through different categories such as images, maps, news articles, products, content in books, videos etc., For ex: If you search for the term Planet Earth in the news category, the result will include only news articles that contain those keywords. But now google grown up with extraordinary search result with multi category search.
Google search has two important factors
- What data is going to be displayed in the search?
- In which order the content are displayed ?
What data is going to be displayed in the search?
First we will see which mechanisms Google uses to find out the correct content for your search. Before that we need to know how the files are stored and how they are related.
If you enter the query, search engines use technology such as Hadoop to manage and query large amounts of data very quickly by creating index for all pages. Here indexing means linking of relevant pages with respective to the category & keywords. The content has now been indexed. Google now has taken a copy of it and placed in your client side. Great, it can now be found and displayed when matching a relevant search query. For ex: If you want to search Tamil songs so you started typing Tamil at that time relevant list automatically get loaded like Tamil songs, Tamil videos, Tamil movies etc., Here Tamil is a keyword. So After typing a keyword, search engine look results for this keyword, the content almost matches which are indexed & linked together are carried out and displayed as a list. This is how indexing works.
Google uses a special one called Spider. This is a small program that scans web pages and creates indexes of keywords. Once a spider has visited, scanned, categorized and indexed a page, it follows links from that page to another page. Great by this way search engine select the pages to be displayed in your search.
In which order the content are displayed ?
Great, but if you search in google, it will likely have 1000’s of results for your each query. So google decided to order the results going to display as per the relevant query. This is known to be the optimization of your search engine (SEO). To resolve this problem Google sketch an algorithm called Page rank.This algorithm is named after Larry Page, one of the founders of Google. It is designed to do just that sort through hundreds of billions of web pages in their search index, to find the most relevant result in a fraction of a second.
These ranking system is made-up of a series of algorithms that analyze what it is you are looking for and what information to return to you. It depends upon a few factors, namely the frequency & location of keywords within the web page, how long the web page has existed, no. Of pages linked to the page in question. It works by counting the number and quality of link to the page to determine a rough estimate of how important the website is. It assigns a numerical weighting to each of the hyperlinked set of documents with the purpose of measuring its relative importance within the set. The rank value indicates an importance of a particular page. Page rank can be computed either iteratively or algebraically. By assigning page rank depends upon the traffic of the site, the search engine will sort the pages and the results are displayed in that sorted order. This is how the Google search engine works.