What are Web Applications ? (WebApps)

You must have heard of Web Applications for a long time now. Nowadays, you even hear of Web 2.0 Apps. But what exactly are Web Applications and how do they impact you ?

In the early days of the web, web sites consisted of static pages, which severely limited interaction with the user since there was no interactivity or very limited interactivity. In the early 1990’s, this limitation was removed when web servers were enhanced to allow communication with server-side custom scripts. As a result, applications were no longer just static brochure-ware, edited only by those who knew the arcane mysteries of HTML; with this single change, normal users could interact with the application for the first time. The trend towards increased interactivity has continued apace, with the advent of “Web 2.0”, a term that encompasses many existing technologies, but heavily features highly interactive, user centric, web-aware applications.
Web-based applications are computer programs that execute in a web browser environment (the overall environment could be a closed group intranet, or a public network such as the internet). An example of such an application would be an online store such as Amazon.com accessed via Firefox or Internet Explorer. Web applications are popular due to the ubiquity of web browsers, and the convenience of using a web browser as a client, sometimes called a thin client. The ability to update and maintain web applications without distributing and installing software on potentially thousands of client computers is a key reason for their popularity.
To put it even more simply, A Web application is just an application that is deployed on the Web. It is a Web page, or series of Web pages, allowing users to accomplish a task like obtaining information and forms, shopping, applying for a job, listening to Internet radio, or any of the many activities possible on the Web. To use a Web application, a user needs to know a URL for the application, and possibly a name and password. Another way to think of a Web application is a Web site offering a great deal of functionality. A web application can provide any functions that may historically be found on a desktop computer. There are web applications to provide weather information for your locale, to track sales calls for a sales force, or sales expenses, or on any topic at all.