The simple definition of a web application is an application that is delivered to the end user from a web-based server through a large network medium like the Internet. Web applications are very popular today even though they are sometimes limiting in their usage. The popularity of web applications can be singly attributed to their functional ease and economy. These applications can be installed only on one server and can be used by many client computers. The client machines on their part don’t need to have the application or any component installed on their machine.

Web applications are most commonly used in web mails, ecommerce such as retail sales, and discussion boards. For instance, while buying a product from an online store, you only come to a shopping cart and payment screen. This screen is the web application interface. Your local computer doesn’t have any component of the application stored in its memory but you can still click and use the application as if it was on your machine.

From the technical aspect, web applications function at three levels. The web browser is the first tier in the structure, an application coded on some standard web language like PHP or JavaScript constitutes the second tier, and the database acts as the third tier to complete the structure. Web applications dynamically generate a series of web pages that are supported by most browsers. Each interface screen is a static event and each time you submit a page or move to the next page, the application processes the previous page and presents an updated page therefore creating an interactive experience.

A very significant technical advantage of web applications is that they can function regardless of the operating system installed on the client terminal. The problems faced by these applications are with regard to browser setting that might be randomly altered by the end user. Changing font size and color can have a significant impact on the functioning of the web application.

Web applications have also been referred to as Rich Internet applications because of the role the client and the medium play in their functioning. Today, these applications are being used to further business over the Internet. A significant strategy in this regard is one adopted by companies who are now providing paid web access to application that were till now only functional if installed on individual client machines. These companies are called Application Service Providers or ASPs.