QueryString is a special type of string which is used for to passing string as command to the Web search engine which is responsible for to find out the exit information. In easy word it is set of characters input to a computer or Web browser and sent to a query program to recover specific information from a database . On the internet when we are used that QueryString is also known as HTTP QueryString which is part of the set of characters automatically input in the address bar of a dynamic Web site when a user makes a request for information according to certain criteria. On the World Wide Web, all URLs can be broken down into the protocol, the location of the file or program and the query string. The protocol you see in a browser is almost always HTTP. On most Web servers, you can use something like session state server-side. On the client, you can store via cookies. Or in the URL, you can store data via a QueryString.