A web application is a collection of web pages that interact with the user, with each other, and with various resources on a web server, including databases. Before you start building your own web applications, you should be familiar with the concepts which I am going to discuss now.
What is a web application?
A web application is a website that contains pages stored on a web server with partly or entirely undetermined content. The final content of a page is determined only when the user requests a page from the web server. Because the final content of the page varies from request to request based on the user’s actions, this kind of page is called a dynamic page.
Common uses for web applications
Web applications have many uses for both users and developers, including the following:
• Let users find information quickly and easily on a content-rich website. This kind of web application gives users the ability to search, organize, and navigate content as they see fit. Examples include company intranets, Microsoft MSDN, and Amazon.com.
• Collect, save, and analyze data provided by users. In the past, data entered in HTML forms was sent as e-mail messages to employees or CGI applications for processing. A web application can save form data directly into a database and also extract the data and create web-based reports for analysis. Examples include online banking pages, store check-out pages, surveys, and user-feedback forms.
• Update websites that have constantly changing content. A web application frees the web designer from continually updating the site’s HTML. Content providers such as news editors provide the web application with content and the web application updates the site automatically. Examples include the Economist and CNN.