BASIC INFORMATION TECHNOLOGY CONCEPTS IS 524

1. BASIC INFORMATION TECHNOLOGY CONCEPTS IS 524 Chandra S. Amaravadi

2. OUTLINE OF THIS PRESENTATION • Introduction • Hardware • Software • Networks • The internet • IS Architectures

3. INTRODUCTION • information technologies (IT) are building blocks • consist of HW, SW, networks etc. • HW & networks have micro-processor based components • IS consists of IT!

4. HARDWARE

5. VARIETY OF HARDWARE

6. COMPUTER TYPES Computers can be classified by number of users: • Single user systems • PCs, laptops, notebooks and handhelds (smart phones) • Workstations • Multi-user systems • Mainframes(legacy system, host) • Servers

7. HARDWARE ORGANIZATION MEMORY UNIT Central Processor INPUT OUTPUT ALU CU ROM RAM Cache STORAGE

8. HARDWARE Physical components of a computer system ALU – processes instructions using logic circuits RAM – stores current data & programs Control Unit – controls operations by sending signals Clock -- ensures timing of operations I/O devices -- keyboard, secondary storage, monitor Bus wires -- transmit data (in the form of 0’s & 1’s)

9. HARDWARE ISSUES • performance: how to increase it? • reliability: how to achieve it? • scalability: adding capacity • security: physical security, • avoiding viruses/intrusions

10. SOFTWARE

11. SOFTWARE Software/SW Program: Detailed instructions to the computer to control information processing operations. • generally written in a programming language • program listing is called _____ ______. • converted to binary (“m/c” language or _____ • ______) and executed • component is called compiler

12. SOFTWARE Software Open Source Application Software System Software “business” or “productivity” Utility Compilers Operating Systems Customized applications!

13. PROGRAMMING LANGUAGES Generations of Programming Languages 1st - Machine 2nd - Assembly 3rd - COBOL, Fortran, “C” 4th - SQL, Java script 5th - Prolog, Java, VC++, Python

14. OPERATING SYSTEM • Software to control system components • Runs the hardware • CPU, memory etc. • Interacts/monitors users • key board commands • passwords etc.

15. COMPILERS AND UTILITY SW Compiler converts program to m/c. Programs written in languages: Utility software perform support functions e.g. virus checking, backup etc.

16. APPLICATIONS SOFTWARE

17. APPLICATIONS SOFTWARE CUSTOMIZED APPLICATIONS Inventory Accounting Invoicing ……. BUSINESS SOFTWARE Word processing Spreadsheet Email …….. OPEN SOURCE SOFTWARE APPLICATION SOFTWARE SYSTEM SOFTWARE HARDWARE

18. BUSINESS SOFTWARE Software used for a business purpose (productivity). • available for a number of functions • example Powerpoint, Word etc. • integrated under Windows • highly finished -- common “look & feel” • not available for every function • licensing and upgrades are common issues

19. CUSTOMIZED SOFTWARE Special purpose software for specific business function. • Example rate quote, claims processing etc. • Mostly developed in-house or by third party • sometimes customized from business software • current development is in OO languages • More expensive than business sw • In-house applications have components: • interface • business logic • database access

20. OPEN SOURCE SOFTWARE Software available without licensing fee. • aka “shareware” • frequently comes with source code • authored by developers but an institution “governs” • Linux, red hat, Open Source foundation • sometimes subscription/nominal fees • bugs, version proliferation and support are common issues

21. NETWORKING

22. A BASIC COMMUNICATION NETWORK Communication devices Medium Terminals Host

23. COMMUNICATIONS COMPONENTS.. Terminals Terminals are the devices used by users to initiate communications. CommunicationsDevices Perform support functions at each end (e.g. conversion from digital to wireless, multiplexing). Medium Physical medium over which transmission takes place, mostly cable, fiber optic or microwave/satellite. Host computers Provide communication services Communications software Performs network management and protocols (set of signals exchanged before data is sent)

24. TYPES OF NETWORKS Networks are classified as follows: • LANs • Wireless LANs • WANs • VANs • VPN LAN – local area network WAN – Wide area network VAN – Value added network VPN – Virtual private network

25. Printer A Wireless Network Cable modem or DSL Wireless Key security Router Router routes traffic to device ISP Wireless Card Carries out communication functions & protocols

26. WIDE - AREA NETWORK (WAN) In WANs communications take place across geographic distances and often involve multiple modes

27. VIRTUAL PRIVATE NETWORK (VPN) A “private network”/tunnel created within a public infrastructure using encryption

28. INTERNET

29. BACKGROUND The internet had a long history with various developments • Started as a research network • first as Arpanet, then bitnet, NSF net • Released into public domain in 1993 • Publicly owned (ATT, Verizon etc.) • HTML in 1991 • Web technology (web pages) in 1992 • 3b users on the web world wide

30. INTERNET PRINCIPLE NODE (173.75.5.8) NODE (143.45.56.9) NODE NODE Data is broken into packets, routed by routers and sent to destination.

31. INTERNET PRINCIPLES • Thousands of networks connected • networks have hosts • hosts can be PCs, web servers, mainframes • each “host” has a unique IP address • TCP/IP protocols are used for transmission • Data sent as packets • Addressed by hosts • Routed by routers

32. THE INTERNET ARCHITECTURE The internet connects web servers and web clients, via a network of networks DNS server Router INTERNET Host/nodes Web server Web client Web client Web client

33. SOME TERMINOLOGY Browser: A program to access and display web pages. Web-server: computers which can host web sites. Web-client: A computer used to access a web site. Web-site: A location on the WWW with a domain address/a web host. DNS: Domain Name Server or Name server – reference for web site addresses Router: A device to route data packets to destinations. Node: An addressable location on the internet. Could be a host or web server WWW: A network of web servers,

34. IS ARCHITECTURES

35. IS ARCHITECTURE Hardware arranged in different configurations CENTRALIZED:Processing carried by one or more “hosts” (“host-based arch.) DISTRIBUTED:Processing shared by several hosts connected by a network CLIENT SERVER:Processing carried by one or more “servers” CLOUD: Applications and data hosted on the internet

36. CENTRALIZED VS DISTRIBUTED Host Centralized Distributed

37. CLIENT SERVER ARCHITECTURE CLIENT CLIENT requests SERVER e.g. mail, database data/service CLIENT CLIENT:Any computer that requires a service. SERVER: Any computer that can fulfill a request.

38. CLOUD ARCHITECTURE CLIENT CLIENT requests Cloud data/service CLIENT Internet

39. CONTEMPORARY ARCH. Cloud Sales Order Fulfillment Internet Service Orderentry Intranet web server Database server Apps. server Internet web server Firewall Purchasing Inventory Web design printer support printer Warehousing Finance Marketing Financial planning Accounts payable Central hub Shipping Accounts receivable Research & planning Credit printer printer Sales Advertising Accounting

40. DISCUSSION QUESTIONS • Why is hardware important for information systems? • What issues does software present to organizations? • What might be the sixth generation programming language? • When in MS Word, user presses “save” what sw are involved in saving? • What happens to the internet if all DNS servers fail? • In a certain less developed country there is limited access to internet. What should the government do? • Is it possible for a country to block off internet traffic coming from outside?, how? • In McDonald’s restaurants, all local processing in each of their restaurants is done by a local host, but financial data is sent to a mainframe at HQ; what arch. is this?