Transcript Internet

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The Internet is commonly identified as the “Network of
networks.” It is a worldwide collection of networks,
gateways, servers and computers, which uses a common
set of telecommunication protocol to link them together.
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The Internet allows services such as electronic mail (e-mail),
chat, and even video and audio communication.
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Many networks connected together, all using the same
method of communication
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A public network
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Began in the 1960s
USES OF INTERNET
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Communication
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Types of Communication
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Email
Instant Messaging
Blog
Discussion group
Internet telephony
Information
 Entertainment
 E- Commerce
 Services
 Education
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Education
 Remote Access
 Collaboration
 File Sharing
 Streaming Media
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WHAT YOU NEED TO CONNECT TO THE
INTERNET:
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Web browser
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Internet explorer
Opera
Mozilla Firefox
Safari
Chrome
Netscape Navigator
ISP – Internet Service Provider
Computer
Modem
INTERNET SPEED
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Bandwidth- is a measure of data flow of the
internet and other digital networks in bits of data
per second, in kilobit per second(kbps), or
megabits per second (mbps)
NARROWBAND AND BROADBAND
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Dial-up connection has a low rate of 56kbps, at
this rate the data flow is considered and is called
narrowband.
DSL internet connection is measured in mbps
and is considered as high speed and has greater
information capacity called broadband.
DATA TRANSFER
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Download is to access and received data from a
remote computer. It is the transfer of a file from
one computer to another.
Upload : is the process of sending data from one
computer such as an internet server or a website.
For example, uploading videos to youtube.
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Major Software Concepts of the Internet
Web Server
A Web Server is a computer that responds to the
requests from Web Browsers. Servers transfer text files and
corresponding graphics and transfer this data to remote
computers that are running Web Browser.
Web Browser
A Web Browser is an application that allows users to
view document within a hypertext. Web Browsers allow text
and graphics to be viewed and formatted beside each other.
The web supports transfer of files of many different data
types; some data types supported by the Web include text,
graphics, and multimedia.
Client/Server Concept
A web browser requests a web page from a web server; the web
server returns the requested file or files to the clients
Web Browse requests
www.course.com/index.html
Web Server
www.course.com
The
Internet
Web
page:
index.
html
The World Wide Web
Massive accumulation of information stored on
computers around the globe in web pages or hypertext
documents, along with graphics, sound, and other
multimedia files. Developed around 1990.
WWW Terminology
Surfing – browsing or navigating the Web through
pages of information.
Web Page – an electronic document written in an
Internet language that depicts information.
Website – collection of related web pages usually controlled
and maintained by a single organization.
Hypertext or Hyperlinks – an underlined text or an image
(indicated by a pointing hand cursor) that lets you jump
from one web page to another.
Static Web Pages – existing HTML(HyperText Mark Up
Language) pages that are stored in the server’s drive.
Dynamic Web page – HTML pages that are created,
dynamically on the fly, as a response to a request by an
application.
HyperText Transfer Protocol (HTTP) – the standard protocol
used for transferring hypertext pages. Browsers and servers
use the HTTP to communicate.
Using Web Browsers
Browser requests a web page by sending a URL (uniform
resource locator) over the Internet to the server
Parts of the URL
A URL contains the protocol used, the host name of the web
server, the network name, and the path and filename of the
requested file.
Domain Name
Folder
http://www.course.com/myfolder/myfile.html
Protocol
Host
Name
Network
Name
File Name
DOMAIN NAMES SUFFIXES AND COUNTRY
CODES
.com = commercial site
.org = organizational site
.gov = government site
.edu = educational site
.mil = military site
.ph = Philippines
.au = Australia
.ca = Canada
.uk = United Kingdom
.pro = professional site
TYPES OF WEBSITES
Portal
 News
 Informative
 Ecommerce
 Education
 Entertainment
 Personal
 Wiki
 Weblog
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The Toolbar Buttons
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Back Button - returns the user to previously
visited site.
Forward Button - returns the user to a visited
page a step forward.
Home - loads well-known home pages.
Reload or Refresh - reloads the web page,
especially at times when the browser encounters
errors during loading.
Print - used to produce a hard copy of the
currently loaded web page.
Stop Button - stops the browser from loading the
current page.
Bookmarks Or Favorites - where the user can
record the addresses of website to be revisited.
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Address Bar - this is where the user types in
the address of the website or the URL to be
visited.
Status Bar - the bar located at the bottom of
the web browser, which displays information
about the status of the request being
processed.
Scroll Bar - allows users to view a wide or
long web page.
DANGERS OVER THE INTERNET
Email spam= also known as junk email is usually
unsolicited commercial email sent from one
source with identical message sent to multiple
recipient.
 Email spoofing= deceitful email practice in which
the sender address is changed so that is would
appear as it comes from a different source
usually someone you know.
 Phishing= practice of trying to get confidential
information such as passwords and usernames
and credit card details by looking as if it comes
from a trustworthy source
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Pharming= attack on website which directs all
traffic to that website to another fictitious
website.
 Spyware: this is a computer program that is
installed covertly on a personal computer to
collect information or even take control over the
computer without the knowledge of the user.
 Computer worms= dangerous computer program
that replicates itself through a network. Some
worm delete files, other disrupts the network
function and still other send junk mail from
infected computer.
 Trojan horse= malicious software fronting to
perform a good task but covertly perform
undesirable function.
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Computer virus: a program that duplicate itself
and then infects the computer.
Hacker : this is a person who is able to enter and
control into the other people’s computer without
authorization