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) and executed
component is called compiler

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

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

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

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
……..
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.
Communications Devices
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 LANs Wireless LANs WANs VANs VPN
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. A Wireless Network Printer ISP Wireless Card 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 NODE (173.75.5.8) (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
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 Finance Marketing
Internet
Service
Order entry
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?
When in MS Word, user presses “save” what sw is involved?
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?
What correspondence is there between diagram on last page and organizational concepts (which concepts)? explain