Transcript Understanding Computers, Chapter 8

Understanding Computers
Chapter 8
The Internet and the
World Wide Web
Learning Objectives
• Discuss how the Internet evolved and what it is like
today.
• Identify the various types of individuals, companies,
and organizations involved in the Internet community
and explain their purposes.
• Describe device and connection options for
connecting to the Internet, as well as some
considerations to keep in mind when selecting an ISP.
• Understand how to effectively search for information
on the Internet and how to properly cite Internet
resources.
• List several useful things that can be done using the
Internet, in addition to basic browsing and e-mail.
• Discuss censorship and privacy and how they are
related to Internet use.
2
Overview
• This chapter covers:
– The evolution of the Internet
– The Internet community
– Different options for connecting to the Internet
– Internet searching
– Common Internet applications beyond Web
browsing and e-mail
– Censorship and privacy issues
3
Evolution of the Internet
• Internet: Largest and most well-known computer
network, linking millions of computers all over the
world
– Furnishes a standard way of sending messages
and information across virtually any type of
computer platform and transmission media
– While Internet has become a household word only
during the past decade, it has actually operated in
one form or another for much longer than that
4
Evolution of the Internet
• ARPANET: The predecessor of the Internet, named
after the Advanced Research Projects Agency
(ARPA), which sponsored its development
– Initially connected four supercomputers
– Eventually grew into today’s Internet
• The World Wide Web: The collection of Web pages
available through the Internet
– Proposed by Tim Berners-Lee in 1989
– Originally only text-based content
– Release of the graphical Mosaic browser in 1993
led to graphical content
– Wide variety of content available via Web pages
today
• Internet2: Researches advanced Internet applications
and technologies
5
Evolution of the Internet
6
The Internet Community Today
• Most members of the Internet community fall into one
or more of the following groups
– Users: People who use the Internet
– Internet service providers (ISPs): Provide access to
the Internet, typically for a fee
7
The Internet Community Today
– Internet content providers: Supply the information
that is available on the Internet
• Businesses and schools
• Government
• Individuals
– Application service providers (ASPs): Provide
access to Web-based software applications
– Web services: Added to Web pages to provide
specific services for end users
– Infrastructure companies: Own or operating the
physical structure of the Internet
– Hardware and software companies
– The government and other organizations
• Internet Society, ICANN, W3C, etc.
8
Myths About the Internet
• Myth 1: The Internet is free
– Most people and businesses
pay for Internet access
– Free services are often in
exchange for providing
contact information or
viewing advertisements
– Fee-based content is
growing
– Micropayments may be
implemented in the future for
Web content
9
Myths About the Internet
• Myth 2: Someone controls the Internet
– No single entity controls the Internet
– Governments can somewhat regulate Internet use
within its country but difficult to control it well
• Myth 3: The Internet and World Wide Web are
identical
– Internet = physical network
– WWW = one resource (Web pages) available via
the Internet
– Other resources are available via the Internet
• e.g. FTP
10
FTP
11
Getting Set Up to Use the Internet
• Typically involves three decisions:
– Determining the type of device you will use to
access the Internet
– Selecting the type of connection desired
– Deciding on the Internet service provider to be
used
• Once these determinations have been made, your
computer can be set up to access the Internet
12
Type of Device
• Possible devices include:
– Desktop, notebook, or
tablet PCs
– Internet appliances
– Mobile devices
– Gaming devices
13
Type of Connection and Internet Access
• Connections can be:
– Dial-up
• PC has to dial via a phone line to connect
• Conventional dial-up
– Slower, but cheaper
– Ties up phone lines
– Relatively secure from hackers
• ISDN
– Faster, but pricey
– Doesn’t tie up phone line
– Used by businesses and individuals
14
Type of Connection and Internet Access
– Direct (always on)
• PC is continually connected to the Internet
• Direct connections are typically broadband
• Used in the home and office
• Because you are always connected, it is
important to protect your computer from hackers
15
Direct Connections
• T1 lines: High-speed, usually used by schools and
large businesses
– T3 lines are even faster
• Cable: Most widely used home broadband connection
• DSL: Broadband delivered over telephone lines
– Must be less than 3 miles from a switching station
– Transmits over telephone lines but does not tie up
the line
• Satellite: Broadband option for rural areas
– Slower and more expensive that cable or DSL
– Available in many areas other broadband options
are not
16
Direct Connections
• Fixed wireless: Uses radio transmission towers rather
than satellites
– Not available in all areas
– Expected to use WiMAX
• Broadband over Fiber (BoF): Delivers over fiber-optic
cabling all the way to the building
– Available in limited areas
– Fast but expensive
• Mobile wireless: Access via mobile phone or device
• Hotspot: Public wireless networks
– Both free and fee-based are available
– Currently Wi-Fi so short range, but WiMAX may
soon be an option
17
Hotspots
18
Common Types of Internet
Connections
19
Selecting an ISP
20
Setting Up Your PC
• To set up your PC
– Install necessary hardware
– Install necessary software
– Select user name, access telephone number (for
dial-up connections), and a payment method
– Perform any necessary set-up to share the
connection with other computers or devices
21
Searching the Internet
• Effective Internet searching: A very important skill
• Search sites: Web sites that help you find Web pages
containing the information you are seeking
• Typically use a search engine in conjunction
with a database containing information about
Web pages to locate appropriate Web pages
• Many search sites available
• Real-time search engines are emerging
– Search the Web live rather than relying on a
database
22
Searching the Internet
• Keyword search
– Keywords are typed in a search box to locate
information on the Internet
– Matching Web pages are called hits
– Clicking on a Web page name displays that page
• Directory search
– Categories are selected to locate information on
the Internet
• Some search sites search multiple search sites
(metasearch sites) and others allow natural language
searches
• Many search sites contain additional tools
– Search for music files, image files, newsgroups,
news articles, maps, people, telephone numbers
– Google is one of the most versatile search sites
23
Searching the Internet
24
Search Site Tools
25
Search Strategies
• Use phrase searching (more than one keyword)
26
Search Strategies
• Use Boolean operators (AND, OR, NOT)
• Use multiple search sites
• Use appropriate keywords
• Use synonyms (different words that mean the same
thing)
• Use variant word forms (variations of your keywords,
alternate spellings, etc.)
• Use wildcards (such as * to search for keyword
patterns)
27
Search Strategies
• Use field searches (searches limited to a particular
characteristic, such as page title, page text, URL, or
domain)
28
Evaluating Search Results
• The quality of a hit can be preliminarily evaluated by
looking at:
– Page title and description
– Company or organization hosting the page
• General guidelines for evaluating a Web page include
considering:
– Source
– Author
– Timeliness
– Accuracy
29
Evaluating Search Results
30
Citing Internet Resources
• To avoid plagiarism, proper citation procedures should
be used for all Internet content used in a paper, book,
or on a Web site
• Plagiarism is discussed in more detail in Chapter 16
31
Beyond Browsing and E-Mail
• Many other activities available via the Internet in
addition to Web browsing and e-mail
– Online communications
– Social networking
– Online shopping and investing
– Online entertainment
– Online news, reference, and information
– Online education and writing
32
Types of Online Communications
• Types of online communications
– Instant messaging (IM): Exchange of real-time
messages
• Buddy list
• Presence technology
33
Types of Online Communications
– Voice over Internet
Protocol (VoIP):
Making telephone
calls over the
Internet
• PC to PC
• Voice over Wi-Fi
• Permanent setups
34
Types of Online Communications
– Discussion groups (message boards, newsgroups,
or online forums): Read and post messages
– Chat rooms: Multiple users chat in real time
– Videoconferencing: Two-way conference using
computers and communications technology
– Webinars: Web seminar, more one-way
– Blogs (Web log): Post short, frequently updates
entries in chronological order
35
Social Networking
• Social networking sites: Create a community of
individuals with common interests
– MySpace, Facebook, etc. allow people to post
information about themselves
– Video and photo sharing (YouTube, Flickr, etc.
– Collaborative news communities (Digg)
– Social bookmarking (del.icio.us)
– Used for politics and business
• Business networking sites
• Family networking sites
• Users should be careful not to reveal too much about
themselves for safety reasons
36
Social Networking
37
Online Shopping and Investing
• E-commerce: Online financial transactions
• Precautions
– Be sure all e-commerce activities are performed via
a secure Web server (https://)
– Use a credit card whenever possible
• Online shopping: Purchasing goods and services
online
– Can purchase items via manufacturers, large
businesses, small businesses, etc.
– Usually paid via credit card, though other options
may be available
38
Online Shopping and Investing
• Online auctions: Buying via an auction format online
(eBay, etc.)
– Buy from individuals
– Can bid until auction closes
– Buyer arranges payments and delivery with seller
– Seller pays auction fees
• Online banking (transfer funds, check balances, pay
bills, etc.)
• Online investing (buy and sell stocks, bonds, and
other securities
– Online portfolios
– Some stock quotes are delayed
• Auction and stock quote pages may need to be
reloaded to show current data
39
Online Shopping and Investing
40
Online Entertainment
• Online music
– Internet radio stations: Listen to music live
– Online music stores: Used to purchase and
download music singles and albums in digital
format legally
– Some available legally via peer-to-peer (P2P) file
sharing services
• Online TV, online videos, video-on-demand (VoD)
– Live TV, full episodes
– Music, news, home videos, etc.
– VoD: Movies and other video content ordered and
delivered on demand
• Online gaming: Games played over the Internet
– Web-based games, online multiplayer games, etc.
41
Online Entertainment
42
Online News, Reference, and
Information
• Online news
– Available through Web sites belonging to news
organizations, television networks, newspapers,
magazines, etc.
– News sites are usually regularly updated
throughout the day
– News archives are often available (sometimes
requires a fee)
• Reference sites
– Provide access to specific types of useful
information
– Phone and address directories, weather, maps,
home values, encyclopedias, dictionaries, etc.
43
Online News, Reference, and
Information
44
Portal Pages, RSS Feeds,
Podcasts, and Widgets
• Portal Web page: Designed to be displayed as a
browser’s home page and visited on a regular basis
– Often contain
news,
calendars,
e-mail, and
other tools
– Usually
personalized
– iGoogle,
My Yahoo!,
My MSN, etc.
45
Portal Pages, RSS Feeds,
Podcasts, and Widgets
• RSS (Really Simple Syndication): Delivers news,
podcasts, and other regularly published content
– Individuals subscribe to an RSS feed and new
content is delivered to them as it becomes
available
• Podcasts: Recorded audio or video available via the
Internet
– Prepared by individuals and companies
• Widgets: Small programs displayed on portal pages,
desktops, dashboards, etc.
– Can be used to display headlines, among other
uses
– e.g. Windows Vista gadgets
46
Product, Corporate, and
Government Information
• The Web is a
useful tool for
locating product
and corporate
information, as
well as
governmental
information and
publications
47
Online Education
• Online education: Using the Internet to facilitate
learning
– Web-based training (WBT): Instruction delivered
via the Web
• Corporate training, tutorials, etc.
– Distance learning: Students take classes from
location other than campus
• Advantages: Self-paced instruction, flexible
location, up-to-date material, immediate
feedback, and customized content
• Disadvantages: Technology requirements and
problems, anonymity, and lack of face-to-face
contact
48
Online Education
• This textbook has:
– Web site at www.course.com/uc12
with interactive activities, practice
tests, etc.
– Blackboard
learning platform
– SAM 2007
testing, etc.
49
Online Education
– Online testing: Taking tests via the Internet
• Available for both objective and performancebased exams
• Typically are
graded
automatically
• Security is an
issue
– Authorized
testing centers
– Secure
testing systems
50
Online Education
– Online writing
• Blogs: Personal Web logs
• Wikis: Editable collaborative Web page
• E-portfolios: Personal online portfolio
51
Censorship and Privacy Issues
• Censorship issues
– Some countries block some Internet content
– Free speech vs. offensive or indecent materials
– Internet filtering: Using software or browser options
to block access to particular Web pages or types of
Web pages
• Used by individuals, schools, employers, public
computers, etc.
• Can use browser settings or special filtering
software
52
Internet Filtering
53
Censorship and Privacy Issues
• Web browsing privacy: Privacy of Web activities
– Cookies: Small files stored on the user’s hard drive
by a Web server
• Add functionality (such as shopping carts and
personal preferences) to Web sites
• Can be used to track Web activity
• Cookie information can be personally
identifiable or non-personally identifiable
• Cookie data can be viewed or deleted
• Cookie settings can be changed and software
can be used to manage cookies
54
Cookies
55
Cookies
56
Censorship and Privacy Issues
• Web bugs: Small, usually invisible, images on a Web
page that transmits data to a Web server
– Difficult to spot or stop
– Software can be used to notify you when Web bugs
are being used
• Spyware: Software that transmits data secretly
through the user’s Internet connection
– Can be blocked and/or removed using security
software (discussed in Chapter 9)
• Adware: Software supported by onscreen advertising
– Often included in free programs
57
Censorship and Privacy Issues
• E-mail privacy: Privacy of the e-mail messages you
send and receive
– Only encrypted e-mail can
be transmitted privately
– Employers and ISPs have
access to the e-mail you
send through those
organizations
– Businesses and ISPs
typically archive e-mail
messages
58
Summary
• Evolution of the Internet
• Getting Set Up to Use the Internet
• Searching the Internet
• Beyond Browsing and E-Mail
• Censorship and Privacy Issues
59