A Web application is any computer program that performs a specific function using a Web browser as a client. The application can be a simple contact form on a website or as complex as a word processor.

What are the advantages of using web applications? A Web application relieves the developer of the responsibility of creating a client for a specific type of computer or a specific operating system, so that anyone can use the application while having access to the Internet and then to a web site.

Their commonly use a combination of server-side scripts (ASP, PHP, etc.) and client-side scripts (HTML, Javascript, etc.) to develop the application. The client-side script is about presenting information, while the server-side script takes care of more complicated things like storing and retrieving information.

Most Web applications rely on the client-server architecture in which the client enters information while the server stores and retrieves information. Internet mail is an example.
In recent years, there has been a huge push for the development of web applications for functions that normally do not require a server to store information.

Web applications can provide the same functionality and gain the advantage of working across multiple platforms. For example, it can act as a word processor, store information in the cloud, and allow you to “download” the document to your personal hard drive.