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Office and Internet Applications: Internet Applications
4. Internet Services and Resources
The Internet provides various services and resources. In this section, we shall discuss how to find
what you need, the major Internet applications and ways you can use the Internet to
communicate with people, including e-mail, newsgroup, etc…
4.1 World Wide Web
The World Wide Web (WWW) is a collection of electronic files among web servers on the
Internet. By establishing a linked relationship between Web documents, related information
becomes easily accessible.
4.1.1
Hypertext Transfer Protocol (HTTP)
The primary function of HTTP is to establish a connection with a Web server and transmit
HTML pages or any other files to the Web browser.
Web
Browser
Web Server
(HTTP server)
1. HTTP
Request
2. HTML
page
TCP connection
IP packets
Web browsers communicate with Web servers via the TCP/IP
protocol. The browser sends HTTP requests to the server, which
responds by sending back messages and HTML pages.
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4.1.2
Hypertext Markup Language (HTML)
Web documents are created using HTML which is a markup language, or tags, which is used to
create Web pages. HTML tells the Web browser how to display the text contained in the Web
pages. There are a number of user-friendly web authoring software, such as Dreamweaver, that
allow you to generate HTML documents. The tags are inserted automatically for you in the web
authoring software.
Over the last decade, billions of Web pages have been created with HTML. Now, however, the
World Wide Web Consortium has posted a more feature-rich standard – XHTML. HTML and
XHTML are both widely accepted and used by Web developers.
4.1.3
Hyperlink
In order to link Web pages to each other on the Internet, hyperlinks are used. Hyperlinks are
instructions that point to other HTML documents, to another section of the same document (i.e.
Bookmark) or to other multimedia elements on the Web.
4.1.4
Searching for Information on the Internet
Basic strategic on searching
Basically, there are two ways to search information on Internet by web browser. They are search
engines and web directories.
There are different web search strategies that help users to find information. A search engine is a
software program that finds web sites and web pages. There are thousands of search engines
exist. Some search on any topic and others are restricted to certain subjects, such as finding
people or job hunting.
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Popular search engines
Search Engine
Web address
AltaVista
http://www.altavista.com
Excite
http://www.excite.com
Google
http://www.google.com
MSN Internet Search
http://microsoft.msn.com
Yahoo
http://www.yahoo.com
Effective Search Techniques
To find information on the Internet efficiently, you had better read the search rules first because
each search engine has different rules for formulating the inquiry. Besides, you can get results
with more than one search engine. The results vary significantly between search engines, because
their databases are compiled in completely different manners.
Different results of the search contained
from Yahoo and Google
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1. By keywords or phases
It is the most widely used search method. The keywords and phrases you enter are critical to the
success of your search. Choose them carefully and try to be as specific as you can.
o
Search Operator: You can use search operators in search expression. They are AND, OR and
NOT.
Search Operators
AND
OR
NOT
o
Example
China AND Canada
China OR Canada
China NOT Canada
Explanation
Find results with both China AND Canada
Find results with China OR Canada
Find results with China except Canada
Wildcard Character: You can also use wildcard characters. Most search engines support these
wildcard characters in their search expressions. A wildcard character allows you to omit part
of a search term. Many search engines recognize the asterisk (*) as the wildcard character.
For example, the search expression “wom*n” would return pages containing both woman and
women.
o
Advanced Search: Many search engines have “Advanced Search” feature, which offers
numerous options for making your searches more precise and getting more useful results.
Users can search the results of web pages which are written in a certain language, created in a
certain file format, that have been updated within a certain period of time, etc… See the
following figure.
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2. Web directory
Web directories use a completely different approach from search engines to build useful indexed
of information on the Web. It is a listing of hyperlinks to Web pages that is organized into
different categories. Users can click an appropriate category to find the information you want.
There is plenty of useful and good quality information on the Internet. However, users may enter
some harmful web sites and see some incorrect or indecent information by mistake carelessly.
For example, methods of committing suicide had sometimes been introduced on web sites and
sexual web-sites are plenty in the Internet. Besides choose carefully, we may avoid enter those
web sites erroneously by screening them out using filtering software. In order to read only
correct and good information on the Internet, we need to choose carefully and seek help from
teachers when necessary.
4.1.5
File Transfer Protocol (FTP)
The File Transfer Protocol (FTP) allows users to download and upload files on the Internet. An
FTP server is a computer that allows users to upload and download files using FTP. An FTP site
contains electronic files including text, graphics, audio clips, video clips and program files that
reside on an FTP server.
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You must have an authorized account (username and password) in order to access the FTP sites.
Many FTP sites have anonymous FTP, i.e. anyone on the Internet can transfer files without prior
permission.
Using a Browser to Access FTP Site
In the Microsoft Internet
Explorer, type the Web address
of FTP site
FTP Client Program
Users can download file using an FTP client program, such as WS_FTP LE program.
FTP site address
Anonymous login selected
Type your e-mail address
Click the “New” button in the Session Properties dialog box. Some ftp site allow anonymous logon.
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Download button
Winzip files
Upload button
Message Area
Toolbar
4.2 Electronic Email (E-mail)
E-mail is a common communications method in our society. Users can send and receive e-mail
with anyone who has an e-mail address. We can use e-mail software or web-based e-mail to send
or receive e-mail. The former one, such as Microsoft Outlook, enables e-mail though a program
running on your computer. Web-based email is handled through interaction with a web site, such
as Yahoo!
Yahoo! Mail is one of the
popular web-based e-mail
Rabbit1.jpg
Users can attach a file.
Rabbit.jpg will be appended
into the email.
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The advantages of using e-mail client program are that e-mail can be integrated with other
applications such as a calendar and task list. Besides, it can sign or encrypt e-mail message by
sender, so that it provides better security level over using the Web-based e-mail approach. For the
Web-based e-mail, it is easily accessible from any Internet-connected computer in the world.
4.2.1.
Email Address
An e-mail address is a combination of a user name and a domain name that identifies a user so he
or she can receive Internet e-mail. An @ (pronounced at) symbol separates the user name from
the domain name.
[email protected]
Username
Domain Name
The followings are several commonly used protocols for sending or receiving email.
Simple Mail Transfer Protocol (SMTP)
SMTP decides which paths an e-mail message takes on the Internet. It handles outgoing
message.
Post Office Protocol (POP)
POP handles incoming messages. POP3 is the latest version of POP, which provides a message
store that holds incoming e-mail until users log on and download it.
Other protocols
Internet Message Access Protocol (IMAP): IMAP is another protocol for retrieving mail message
from a server.
Multipurpose Internet Mail Extensions (MIME): MIME specifics how to encode non-text data,
such as graphics and sound, so it can travel over the Internet.
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4.3 Newsgroup
A newsgroup just likes a bulletin board. There are tens of thousands of newsgroups entertain
global discussions on thousands of topics, including your favourite celebrities or professional
teams. Newsgroups are organized by topic. The topic, and sometimes subtopics, is embedded in
the newsgroup name.
To participate in a newsgroup, user needs newsreader software or similar software that is built
into most Internet browser clients. Nowadays, many newsgroups are maintained within the
World Wide Web and newsreader software is not required.
Name of
newsgroup
Name of
topic
Name of
Sub-topic
Newsgroup.computer.hardware
Generally, newsgroups are public, anyone can post message and any posted replies to that
message as a thread. It is a series of messages that are replies to each other.
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Original Message
Threads
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4.4 Online Chat
4.4.1
Chat Rooms
An online chat is a real-time typed conversation that takes place on a computer. A chat room is a
location on an Internet server that permits users to chat with each other. Anyone in the chat room
can participate in the conversation, which usually is specific to a particular topic. Users only
need to type a line of text on their computer keyboard, the words they enter display on the
computer screens of other people in the same chat room. Some chat rooms support voice chats
and video chats, in which people hear or see each other as they chat.
4.4.2
Instant Messaging (IM)
Instant messaging is a real-time Internet communications service that notifies you when one or
more people are online and then allows you to exchange messages or files or join a private chat
room with them.
Send an instant
message
Add people to the
messenger list.
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Join a chat
room
ICQ
ICQ (pronounced “I seek you”) is one of the most popular instant messaging software programs
available. Users can use ICQ for text chats, to send e-mail message, and to exchange files and
URLs with other users. In addition, ICQ lets users chat with groups of people to participate in
group meetings or to play games.
4.5 Webcasting
Many companies use push Technology to webcast, or broadcast news. Web broadcasting is
streaming audio or video over the Internet. Live or pre-recorded events can be transmitted to an
unlimited worldwide audience. Streaming is a technology that refers to the continuous
transmission of data, typically audio or video.
Viewers only need the browser plug-ins from Real Player, Windows Media Player or QuickTime
player to watch video. They also need a pair of speaker to hear the audio.
RTHK Web site has
broadcasting Radio
and TV
Plug-in
Most Web browsers have the capability of displaying basic multimedia elements on a Web page.
Sometimes, a browser might need an additional program, called a plug-in. Plug-in enables Web
browsers to display or play a specific files, such as audio or video, that you request. When you
install a Web browser, many popular plug-ins are often installed with it. When you encounter a
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Web page that requires a plug-in you do not have, the Web page might display a message telling
you that you are missing a required plug-in, or a dialog box might open and provide a way for
you to install the missing plug-in.
Missing plug-in
name
Common plug-in applications
Type
Document
Multimedia
Plug-in Application
Description
Acrobat Reader
View, navigate and print Portable
Document Format (PDF) files.
Flash Player
View dazzling graphics and
animation, hear outstanding sound
and music, display Web pages across
an entire screen.
QuickTime
View animation, music, audio,
video, etc… directly in a Web page.
RealOne Player
Shockwave Player
Windows Media
Player
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Listen to live; stream audio and
video content for faster viewing;
play MP3 files; create music CDs.
Experience dynamic interactive
multimedia, 3-D graphics and
streaming audio.
Listen to live and audio; play or edit
WMA and MP3 files; burn CDs;
watch DVD movies.