A web search engine is a software which is designed to search information on the World Wide Web (WWW).
The search results are often referred to as search engine results pages (S E R Ps). The information may be a mix of web pages, images, or other types of files. Some search engines also mine data available in databases or open directories. Unlike web directories, which are maintained only by human editors, search engines also maintain real-time information by running an algorithm on a web crawler.
Search Engines play a very important role for every website to get its traffic audience. Each and every website owner wants to be in the top page of the search results. And This is done by S E O process. Now the question arises that what is S E O? lets have a brief look on this.
S E O -Search engine optimization is the process of affecting the visibility of a website or a web page in a web search engine’s unpaid results often referred to as ” natural “, ” organic”, or “earned” results. In general the earlier and more frequently a site appears in the search results list. The more visitors it will receive from the search engine’s users. Few of these visitors can then be converted into customers.
The leading search engines such as Google, Bing and Yahoo use crawlers to find pages for their algorithmic search results. Pages which are linked from other search engine indexed pages do not need to be submitted because they are found automatically.
To avoid undesirable content in the search indexes, webmasters can instruct spiders not to crawl certain files or directories through the standard robots.txt file in the root directory of the domain