2440: 141 Web Site Administration

1. 2440: 141Web Site Administration Introduction to Web Applications Instructor: Enoch E. Damson

2. Information System • A collection of components that work together to process data into accurate information using the information processing cycle • Information processing cycle – involves: • Input • Processing • Output • Storage Introduction to the Web Applications

3. Information System Components • The main components of an information system are: • Data – collected data and facts used as inputs for system processing • Procedures – manual procedures, guidelines, business rules, and policies implemented in the system • Hardware – computer systems and devices • Software – applications, operating systems, and any other utilities used • Network – communication infrastructure to connect client processes to the system • People – users, managers, database administrators, programmers, systems analysts, systems administrators Introduction to the Web Applications

4. Information System Components… Introduction to the Web Applications

5. Information System Usage • A collection of components that work together to process data into accurate information • Can be categorized based on usage • Lower-level management – uses information system to assist management and employees with operational tasks like inventory systems • Middle-level management – uses information systems that deal with midterm goals like forecasting • Upper-level management – works with information systems that assist with long-term decision-making goals Introduction to the Web Applications

6. Information System Usage… Introduction to the Web Applications

7. Information System Usage Categories • Information systems are classified mainly into the following distinct categories based on their usage: • Transaction-processing systems (TPS) – used for operational tasks like order tracking, customer service, payroll, etc • Decision-support systems (DSS) – used for tactical management tasks like sales forecasting, risk management, etc • Expert systems (ES) – captures reasoning of human experts like loan experts, market analysts, etc Introduction to the Web Applications

8. Architecture • High-level plan or strategy for building applications • Can have a number of tiers (usually up to 5 tiers) • The tiers may place data management, application logic, and the user interface into separate processes or combine them in some manner Introduction to the Web Applications

9. One-Tier Architecture • Combines data management, application logic, and the user interface into a single executable file • Many old data processing applications like COBOL programs use this architecture • Current desktop (PC) applications like MS Access applications also use this architecture Introduction to the Web Applications

10. Two-Tier Architecture • Organizes an application into two layers • User interface layer • Data management services layer • The application/business logic may be in either or both layers • Often used in conjunction with client-server computing which has: • Clients – sends requests to the server • Server – manages requests from clients Introduction to the Web Applications

11. Three-Tier Architecture • Cleanly separates data management, application logic, and the user interface into different layers • User interface – manages forms and reports • Data management – holds the database structure • Application layer – holds the application logic Introduction to the Web Applications

12. Tiered Architectures Introduction to the Web Applications

13. Types of Applications • Commonly used types of applications include: • Client/server applications • Data warehouse applications • Web applications Introduction to the Web Applications

14. Client/Server Applications • Provide a flexible and scalable structure that • takes advantage of the processing power of personal computers (PCs) • utilizes the capacity and power of dedicated servers Introduction to the Web Applications

15. Client/Server Architecture • The typical client/server architecture is made up of: • Server – providing services to clients • Clients – requesting services from the server • Business Logic – implementing business rules Introduction to the Web Applications

16. Physical Architecture of Client/Server Applications Introduction to the Web Applications

17. Data Warehouse Applications • Used in decision-support applications to support executive management in decision-making processes • The data warehouse is accessed by software applications or reporting applications called online analytical processing (OLAP) • The OLAP applications retrieve data and generate reports with the capability of data mining • Data warehouse – a collection of many types of data taken from a number of different databases that support various corporate departments • Data mining – set of activities used to find new, hidden, or unexpected patterns in data within a data warehouse Introduction to the Web Applications

18. Physical and Logical Architecture of Data Warehouse Applications Introduction to the Web Applications

19. 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 Introduction to the Web Applications

20. 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 Introduction to the Web Applications

21. Web Application Architecture… • Uses Web browsers as the front ends • Uses the Webto 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 Introduction to the Web Applications

22. Web Application Components • Logical components of Web Applications • Physical structure of Web Applications Introduction to the Web Applications

23. Examples of Web Applications • Examples of Web applications include: • Reservation systems • Weblogs • Massively-Multiplayer Online Role-Playing Game (MMORPG) • Online shopping • Online auction • Games • Multimedia applications • Calendars • Maps • Chat applications • Clocks • Interactive design applications • Stock tickers • Currency converters • Data entry/display systems Introduction to the Web Applications

24. 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 Introduction to the Web Applications

25. 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 Introduction to the Web Applications