A Query String is information sent to the server appended to the end of a page URL which means that Query String is way to transfer information from one page to another through the URL. Query String is attached to the URL with "?".
Advantages:
1. Easy to use.
2. No extra effort is needed to code.
3. No server resources are required
4. All browser supports QueryString
5. Query String is contained in the HTTP request for a specific URL.
Disadvantages:
1. There is a limit to URL length of 255 characters.
2. Query String data is directly visible to user thus leading to security problems