Unit 1
Computers and Society - Past and Present
Under this unit, we’ll be focusing on the basic introduction to computing. We will look at
Chapters 1 and 2 of Discovering Computers.
What is a computer? (slide 5)
A computer is an electronic device, operating under the control of instructions stored in its own
memory.
The components of a computer (slide 7):
Input Device
Output Device
System Unit
Storage Device
Communications Device
In the earlier days, we were taught that computers had four elements: input, process, store,
output; but today, communications is a very important part of the computer system.
Advantages and disadvantages of using computers (slide 9):
Advantages
Disadvantages
Speed
Health Risks
Reliability
Violation of Privacy
Consistency
Public Safety
Storage
Impact on labour force
Communications
Impact of environment
Green Computing (slide 10):
With concerns for the environment, it is critical for us to observe Green Computing. This
involves reducing the electricity consumed and environmental waste generated when using a
computer. There are several strategies to encourage this (see slide 10).
Networks and the Internet (slide 11):
A network is considered to be a collection of computers and devices linked together via
communication devices and transmission media with the intention of sharing resources.
What is the Internet? (slide 12):
This is a worldwide collection of networks that connects millions of businesses, government
agencies, educational institutions, and individuals.
It is used by persons for several different reasons:
- Communicate
- Research and to access information
-
Shopping
Banking and investment
Entertainment (inclusive of social networking)
Downloads
Share information
Web Application
What is software? (slide 15)
Software, also called a program, tells the computer what tasks to perform and how to perform
them. There are two types of software:
- System Software (such as Operating Systems and Utility programs), and
- Application Software (such as Word Processing, Desktop Publishing and Spreadsheet
software.
The process of setting up software to work with the computer, printer, and other hardware is
called installing.
Categories of Computers (slide 18)
Some of the major categories of computers that exist are:
- Personal computers
- Mobile computers and mobile devices
- Game consoles
- Servers
- Mainframes
- Supercomputers
- Embedded computers
Types of computers (this is NEVER to be confused with categories of computers):
Computer can process signals in two ways, either digital or analog.
(a) Digital Computer – this type of computer processes discrete/measurable signals.
(b) Analog Computer – this type of computer processes continuous signals (e.g.
temperature).
(c) The computer that can process both analog and digital signals is called a Hybrid
Computer.
Components / Elements of an Information System (slide 29):
Although we will discuss Information Systems as a topic in the next class, we should know that
an Information System is not a piece of software online. It is comprised of five
components/elements:
- Hardware
- Software
- Data
- People
- Procedures
Computer Applications in Society (slide 33):
Computers are used in several different industries and for various applications, be it for
pleasure of for productivity. Some of the major areas you should be able to discuss how
computers are applicable are:
- Education
- Finance
- Government
- Health Care
- Science
- Publishing (web / graphics)
- Travel
- Manufacturing
History of Computers:
There are two YouTube videos covering the history of computers, but in summary, there are
four generation of electronic computers that exist. Prior to this, there were some fascinating
works by scientists like Charles Babbage (Analytical Difference Engine), Herman Hollerith
(Punch Card), and Blaise Pascal (Pascaline).
The four generation of computers are:
•
•
•
•
First generation (1940s) – consisted of vacuum tubes.
Second generation – Transistors replaced vacuum tubes.
Third generation – utilised Integrated Circuits (IC)
Fourth generation – utilised Very Large Scale Integrated Circuits (VLSIC)
Internet Governance:
Who owns the Internet? It is not owned by any one body, but is overseen by a series of
independent, non-profit organizations to ensure that ethical behavior, legal principles and
standardized regulations are in effect. There are several bodies that govern the internet in one
form or the other. Below see three (3) such examples (ICANN, ISOC, ARIN):
ICANN:
Short for Internet Corporation for Assigned Names and Numbers, a nonprofit organization that
has assumed the responsibility for IP address space allocation, protocol parameter
assignment, domain name system management and root server system management functions
previously performed under U.S. Government contract.
ICANN was created by the late Jon Postel in the fall of 1998 in response to a policy statement
issued by the US Department of Commerce. This statement called for the formation of a private
sector not-for-profit Internet stakeholder to administer policy for the Internet name and
address system.
Thus far ICANN has taken various measures to oversee the domain-name registration system's
transition from government hands to private hands and to coordinate its decentralization and
the integration into a global community.
ISOC:
A non-governmental, non-profit organization dedicated to maintaining and enhancing the
Internet. Through its committees, such as the Internet Advisory Board and the Internet
Engineering Task Force, the Internet Society is responsible for developing and approving new
Internet standards and protocols.
ARIN:
Acronym for the American Registry for Internet Numbers. ARIN, founded in 1997, is a non-profit
organization that registers and administers IP numbers for North America, a portion of the
Caribbean and sub-Saharan Africa. ARIN is one of four regional Internet registries.
Discovering Computers : Chapter 2 (Fundamentals of the WWW and Internet)
We will look at some of the contents of this slide.
The Internet is a worldwide collect of networks that links millions of businesses, government
agencies, educational institutions, and individuals.
The Internet was born from the ARPANET (Advanced Research Project Agency Network) in
1969 for the United States’ Department of Defense (DOD).
Many business and homes connect to the Internet via high-speed broadband Internet service
such as:
- Cable Internet service
- DSL
- Fiber to the premises (FTTP)
- Fixed Wireless
- Wi-Fi
IP Address, domain name, DNS server (slide 12):
An IP address is a unique number that identifies each computer or device connected to the
Internet.
A domain name is the text version of an IP address.
A DNS server translates the domain name into its associated IP address.
Domain Name extensions (slide 13) indicate what type of website is being surfed. Example
.com websites are commercial organizations, .gov represents government agencies, .edu
represents educational institutions and so on.
The World Wide Web (slide 14):
The World Wide Web (or Web) consists of a worldwide collection of electronic documents. A
website is a collection of related web pages and a web server is a computer that delivers
requested web pages to your computer.
Thirteen popular types of websites:
- Portal, News, Informational, Business, Blog, Wiki, Online Social Network, Educational,
Entertainment, Advocacy, Web Application, Content Aggregator, Personal.
E-Commerce (slide 40):
E-commerce is a business transaction that occurs over an electronic network. M-commerce is
the mobile equivalent.
Three types of E-commerce interactions are:
(a) Business-to-consumer (B2C)
(b) Consumer-to-consumer (C2C)
(c) Business-to-business (B2B)
Other Internet Services include (slide 43):
- Email
- Mailing List
- Instant Messaging
- Chat
- VoIP
- Newsgroup
- FTP
End of Unit 1 Lecture Notes