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2440: 141Web Site AdministrationIntroduction to Web ApplicationsInstructor: Enoch E. DamsonInformation SystemA collection of components that work together to process data into accurate information using the information processing cycleInformation processing cycle involves:InputProcessingOutputStorageIntroduction to the Web Applications2Information System ComponentsThe main components of an information system are:Data collected data and facts used as inputs for system processingProcedures manual procedures, guidelines, business rules, and policies implemented in the systemHardware computer systems and devicesSoftware applications, operating systems, and any other utilities usedNetwork communication infrastructure to connect client processes to the systemPeople users, managers, database administrators, programmers, systems analysts, systems administratorsIntroduction to the Web Applications3Information System Components

Introduction to the Web Applications4Information System UsageA collection of components that work together to process data into accurate informationCan be categorized based on usageLower-level management uses information system to assist management and employees with operational tasks like inventory systemsMiddle-level management uses information systems that deal with midterm goals like forecastingUpper-level management works with information systems that assist with long-term decision-making goalsIntroduction to the Web Applications5Information System Usage

Introduction to the Web Applications6Information System Usage CategoriesInformation 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, etcDecision-support systems (DSS) used for tactical management tasks like sales forecasting, risk management, etcExpert systems (ES) captures reasoning of human experts like loan experts, market analysts, etcIntroduction to the Web Applications7ArchitectureHigh-level plan or strategy for building applicationsCan 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 mannerIntroduction to the Web Applications8One-Tier ArchitectureCombines data management, application logic, and the user interface into a single executable fileMany old data processing applications like COBOL programs use this architectureCurrent desktop (PC) applications like MS Access applications also use this architectureIntroduction to the Web Applications9Two-Tier ArchitectureOrganizes an application into two layersUser interface layerData management services layerThe application/business logic may be in either or both layersOften used in conjunction with client-server computing which has:Clients sends requests to the serverServer manages requests from clientsIntroduction to the Web Applications10Three-Tier ArchitectureCleanly separates data management, application logic, and the user interface into different layersUser interface manages forms and reportsData management holds the database structureApplication layer holds the application logicIntroduction to the Web Applications11Tiered Architectures

Introduction to the Web Applications12Types of ApplicationsCommonly used types of applications include:Client/server applicationsData warehouse applicationsWeb applicationsIntroduction to the Web Applications13Client/Server ApplicationsProvide a flexible and scalable structure thattakes advantage of the processing power of personal computers (PCs)utilizes the capacity and power of dedicated serversIntroduction to the Web Applications14Client/Server ArchitectureThe typical client/server architecture is made up of:Server providing services to clients Clients requesting services from the serverBusiness Logic implementing business rulesIntroduction to the Web Applications15Physical Architecture of Client/Server Applications

Introduction to the Web Applications16Data Warehouse ApplicationsUsed in decision-support applications to support executive management in decision-making processesThe 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 miningData warehouse a collection of many types of data taken from a number of different databases that support various corporate departmentsData mining set of activities used to find new, hidden, or unexpected patterns in data within a data warehouseIntroduction to the Web Applications17Physical and Logical Architecture of Data Warehouse Applications

Introduction to the Web Applications18Web ApplicationsClient/server applications accessed with a Web browser over a network like the Internet or an IntranetWeb applications have become popular because of the:platform-independence of Web browsers and Web document formatsability to update and maintain Web applications without distributing and installing software on several client computersIntroduction to the Web Applications19Web Application ArchitectureComposed of:Web browser layer allows users to navigate through Web pages on the InternetWeb server layer responds to requests submitted by the Web browsersApplication server layer used for data processing and interfacing to the business logic and database serverBusiness Logic layer implements business rulesDatabase server layer stores and manages dataIntroduction to the Web Applications20Web Application ArchitectureUses Web browsers as the front endsUses the Web to communicate with the Web serverUses HTTP as the communication protocol between the Web browser and the Web serverUses HTML/XHTML pages created using, ActiveX, Java applets, ASP, JSP etcIntroduction to the Web Applications21Web Application Components Logical components of Web Applications

Physical structure of Web Applications

Introduction to the Web Applications22Examples of Web ApplicationsExamples of Web applications include:Reservation systemsWeblogsMassively-Multiplayer Online Role-Playing Game (MMORPG)Online shoppingOnline auctionGamesMultimedia applicationsCalendarsMapsChat applicationsClocksInteractive design applicationsStock tickersCurrency convertersData entry/display systems Introduction to the Web Applications23Nature of Web ApplicationsWeb applications:have features and benefits of desktop applicationshave some form of programmatic control either on the client side, or on the server, or bothemphasize on real data separation as opposed to markup/style separationare usually smaller in file size than desktop applicationscan have rich graphical-user interfaces (GUI)have reduced client-requirementshave portable data

Introduction to the Web Applications24Building Web ApplicationsTwo major components needed to build web applications include:Hardware platforms could be a single shared server running on a web server and a databaseSoftware platformsSchema for data storageBusiness rule (logic) for accessing and modifying dataInteractive logic for presenting data to usersIntroduction to the Web Applications25