Web Application

A web application or web app is application software which executes through a web browser. While the application resides on a web server. A web application is developed by specific programming languages that are supported by the web browsers. More commonly, the web applications are developed by combining or solely using the languages such as: JavaScript, AJAX, Java, Perl, PHP, ASP.NET and HTML5 etc.

In early days of web based client-servers systems, every application being used had an application program that had to be installed on the client before the application on the server could be accessed. That application program installed on the client was used as an interface.

            Now, the web applications have provided us with the advantages in many ways such as: browser oriented web applications do not require any software installation on the client except the web browser which is pre-installed with the operating system on the pc. Anybody, anywhere on the globe can access the application and be the beneficiary of it. No Hi-Fi computing power is required to use it. All a user has to do is get a pc and an internet connection. There are no time restrictions for its use.

Some web applications are: Data Collecting and Viewing applications, these applications are generally used where data about some person or things is required in the form of various attributes. These applications are directly connected to a database on a server which collects and stores the information in an organized way. Example of these applications is university online registration system, online shopping etc.

Another type of applications is applications created for specific businesses that are well secured and they do not work on the basis of simple saving and retrieving system of data. These applications are built on functions that depend on complex logics and algorithms. These functions perform transactions of funds, bill payment; keeping an account of balance of a customer. These applications include Online Banking, Airline Reservations etc.

Model of Web applications consists of three layers.  The first layer runs on the client which has a basic browser.  The second layer has a dynamic content generating tool like JavaScript or PHP.  The third layer is the overall system where the data is saved and it consists of database software.

Sometimes these layers are referred to as:

·         Presentation

·         Application

·         Storage