Explain the concept of Web Application.

An introduction to web applications
A web application consists of a set of web pages that are generated in response to user requests. The Internet has many different types of web applications, such as search engines, online stores, auctions, news sites, discussion groups, games, and so on.

Properties of web applications

Web applications are a type of client/server application. In that type of application, a user at a client computer accesses an application at a server computer. In a web application, the client and server computers are connected via the Internet or via an intranet (a local area network).
In a web application, the user works with a web browser at the client computer. The web browser provides the user interface for the application. The most popular web browsers are Microsofts Internet Explorer, .Mozilla Firefox
The application runs on the server computer under the control of web server software. For ASP.NET web applications, the server must run Microsofts web server, called Internet Information Services, or IIS.

For most web applications, the server computer also runs a database management system, or DBMS, such as Microsofts SQL Server. The DBMS provides access to information stored in a database. To improve performance on larger applications, the DBMS can be run on a separate server computer.

The user interface for a web application is implemented as a series of web pages that are displayed in the web browser. Each web page is defined by a web form using HTML, or Hypertext Markup Language, which is a standardized set of markup tags.
The web browser and web server exchange information using HTTP (Hypertext Transfer Protocol).