The Concept of Search Engine

Search Engine?
Search Engine is an information retrieval system that allows users to locate the information on the World Wide Web. World Wide Web is seen as a formless database that contains information. World Wide Web is also called an ocean of information; hence getting the correct information from this unstructured database is always a pain. Search Engine makes this easier by managing, filtering and retrieving the appropriate information that exactly what a user needs.

How does a Search Engine Work?
The user enters a keyword or phrase into a search engine, search engine software quickly sorts through literally millions of pages in World Wide Web to find matches to a specific query and finally search engine’s results are displayed in order of relevancy. Search Engines are based on these six components, Spider, Crawler, Indexer, Database, Result Engine and Web Server.

Spider - Downloads web pages.

Crawler –Tracks all of the links on each web page.

Indexer – Examines web pages downloaded by the Spider and the Crawler.

Database– Keeps the information of all downloaded and indexed pages.

Results Engine – Pull out relevant search results from the database.

Web Server –Allows communication between the user and other search engine components.

Whenever a user tries to find particular information using a search engine, asking the search engine program to look into its index of sites and match the keywords and phrases related to the information. Search Engines are very complex systems. They include extremely detailed processes and programs, and are updated all the time. All search engines follow the basic process when conducting search processes, but because they are based on different technologies, the results may not be same depending on which search engine you use. 

How do Search Engines Rank Webpages?

To rank web pages, all Search Engines stick to a certain set of rules. These may vary search engine to search engine. One of the primary goal of Search Engines is to display the most relevant and accurate pages at the top of their lists. For this purpose, they focus on keywords and phrases in the web page document and, sometimes, in the HTML META tags. They look for the title tag and scan the headers and text near the top of the page. Some of them judge the relevancy of page by the number of links that are pointing to sites; the more links, the more relevant is the content, i.e., value of the page.

Conclusion

Search Engines make our job much easier by sorting relevant and accurate information from available pages on the Web, which itself is growing exponentially. Search Engines are very intelligent when it comes to finding information based on unique keywords, phrases, and quotes, as they index web pages word by word. Search Engines are also handy in locating a number of documents. If you want a wide range of responses to specific queries, use a search engine such as, Google, Yahoo, Bing etc.