Web application development is making of programs that are deployed on remote servers and is delivered to the consumer over internet. Web Application is an application like ones that run on your desktop, but on the web. “on the web” means they run on the browser. It is broadly divided into two categories:
- Server Side Scripting: It is the type of coding in which is interpreted or executed by web server located on the remote location. Its code is not visible to general public. Some client side scripting languages are PHP, Perl, Python, ASP and many more.
Web Application Lifecycle is the process of developing a web application and the various stages involved in between. It is mainly of two types:
- System Development Life Cycle (SDLC): is the old process which includes research steps like to identify and define the application requirements, analyzing information, programming, testing and bug fixing, implementation and maintenance.
- Agile Web Application Development: is the iterative development process that focuses to provide a better procedure to allow revisions and evolution of web application requirements. It includes research, analysis, design, programming, implementation, testing, deployment and maintenance.
It organizes a practical approach in application development. The order followed is:
- Defining aim, checkpoints and method.
- Creating functional specifications.
- Defining technical specifications and selecting suitable technology.
- Illustrating application architecture and structure and development methodology.
- Server, hardware and software selection.
- Third party vendor selection, e.g. Payment Gateway, SSL Certificate, etc.
- Designing layout & interface.
- Database structure design.
- Testing its quality, compatibility, security, performance and usability.
- Deployment and maintenance.
A web application is basically a three-layered model.
- The first layer is the user interface on a web browser.
- The next layer is where the dynamic content is generated such as PHP servlets or Active Server Pages (ASP).
- The last layer is the database containing content and customer data.
A request by the user via User Interface moves to the web application server which accesses the databases servers to perform the task on the information stored within the database. The retrieved information is then presented to the user through the browser.
Some of the supporting agents that help in speeding up the development and saving a developer’s effort from starting from scratch are:
- Program Libraries is a collection of commonly used functions, classes or subroutines which helps in developing functionalities in a modular type application.
- Web Application Frameworks are sets of program libraries, components and tools organized in a hierarchical system to apply fast and efficient approach towards web app development.