A web application is an application on a server that is accessed over a network such as the Internet or an intranet. It is an application that uses a web and browser technologies to accomplish one or more tasks over a network, typically through a web browser as a client. Web applications are coded in a browser-supported language like JavaScript, HTML, and dependent on a common web browser to render the application executable. It can be run on most web browsers as it is cross browser compatible. It is convenient when it can be accessed through a browser platform. It is able to update itself and maintain web applications without distributing and installing software on many different client computers. An application can be as simple as a guest sign-in book on a website, password generator, link scanner to more complex such as email, online picture editor, documentation etc. Web applications can provide the same functionality as your system application and gain the benefit of working across multiple platforms. For example, a web application can act as a word processor, storing information and allowing you to download the document onto your personal hard drive.
Application-specific methods such as drawing on the screen, playing audio, and access to the keyboard and mouse are all possible using Java, JavaScript, HTML5, PHP, Flash, Silverlight, web services vs dedicated applications, and other technologies. A more familiar interface is created using all services combined together and general purpose techniques such as drag and drop are also implemented using these techniques. Both client-side and server-side scripting are used to add functionality especially to create an interactive experience. Web applications commonly use a combination of server-side script (ASP, PHP, etc) and client-side script (HTML, Javascript, etc.) to develop the application. The client-side script deals with the presentation of the information while the server-side script deals with all the hard stuff like storing and retrieving the information. Client-server technologies such as PHP and Ajax are used to bring about dynamic content to the web applications. Google Apps, Microsoft Office Live, and WebEx WebOffice are examples of the newest generation of web applications.
There are a great many types of online applications that are available which provides functionality such as message boards, language translator, online document editing, online photo editing, video editing, online file conversion, internet speed test, link shortener, language translator, password generator, online calculator, currency converter, online maps, online file hosting and sharing, website link checking, online file virus scanner, website analysis, contact management, online mindmapping, online lists, etc. to name a few.
