Web application
- 3. • A web application is a software program that runs in an Internet browser, on or through a web page. Similar to a software program that runs on a computer desktop or desktop application, a web application allows for user interaction and can be designed for a variety of uses.
- 4. Web Applications • Client/server applications accessed with a Web browser over a network like the Internet or an Intranet • Web applications have become popular because of the: • platform-independence of Web browsers and Web document formats • ability to update and maintain Web applications without distributing and installing software on several client computers
- 5. Examples of Web applications include • Reservation systems • Weblogs • Online shopping • Online auction • Games • Multimedia applications • Calendars • Maps • Chat applications • Clocks • Stock tickers • Currency converters • Data entry/display systems
- 6. How a Web Application Works • Web applications are usually coded in browser-supported language such as JavaScript and HTML as these languages rely on the browser to render the program executable. Some of the applications are dynamic, requiring server-side processing. Others are completely static with no processing required at the server. The web application requires a web server to manage requests from the client, an application server to perform the tasks requested, and, sometimes, a database to store the information. Application server technology ranges from ASP.NET, ASP and ColdFusion, to PHP and JSP.
- 7. Web Application Architecture • Composed of: • Web browser layer – allows users to navigate through Web pages on the Internet • Web server layer – responds to requests submitted by the Web browsers • Application server layer – used for data processing and interfacing to the business logic and database server • Business Logic layer – implements business rules • Database server layer – stores and manages data
- 8. Web Application Architecture… • Uses Web browsers as the front ends • Uses the Web to communicate with the Web server • Uses HTTP as the communication protocol between the Web browser and the Web server • Uses HTML/XHTML pages created using, ActiveX, Java applets, ASP, JSP etc
- 9. Web Application Components • Logical components of Web Applications • Physical structure of Web Applications
- 10. Nature of Web Applications • Web applications: • have features and benefits of desktop applications • have some form of programmatic control either on the client side, or on the server, or both • emphasize on real data separation as opposed to markup/style separation • are usually smaller in file size than desktop applications • can have rich graphical-user interfaces (GUI) • have reduced client-requirements • have portable data
- 11. Building Web Applications • Two major components needed to build web applications include: • Hardware platforms – could be a single shared server running on a web server and a database • Software platforms • Schema – for data storage • Business rule (logic) – for accessing and modifying data • Interactive logic – for presenting data to users
- 12. THANKS