internet

[internet] [internet services] [classification network] [network architecture] [network topology]

internet

•1. A worldwide collection of networks that links millions of businesses, government agencies, educational institutions, and individuals.

•The largest and most well-known computer network, linking millions of computers all over the world.

The worldwide communication infrastructure that links computer networks using TCP/IP protocol

advantage of internet

§Global Audience
Content published on the World Wide Web is immediately available to a global audience of users. This makes the World Wide Web a very cost-effective medium to publish information. Reaching more than 190 countries.

Operates 24 hours, 7 days a week
You don't need to wait until resources are available to conduct business. From a consumer's perspective as well as a provider's business can be consummated at any time. The fact that the Internet is operational at all times makes it the most efficient business machine to date

§Relatively Inexpensive
It is relatively inexpensive to publish information on the Internet. At a fraction of the cost to publish information by traditional methods, various organizations and individuals can now distribute information to millions of users. It costs only a few thousand dollars to establish an Internet presence and publish content on the Internet.

§Online Surveys
Traditional methods of performing surveys are often relatively slow and expensive compared to online surveys conducted on the Internet.

disadvantage of internet

§Theft of Personal Information
If you use the Internet for online banking, social networking or other services, you may risk a theft to your personal information such as name, address, credit card number etc. Unscrupulous people can access this information through unsecured connections or by planting software and then use your personal details for their benefit.

§Spamming
Spamming refers to sending unwanted e-mails in bulk, which provide no purpose and needlessly obstruct the entire system. Such illegal activities can be very frustrating for you as it makes your Internet slower and less reliable.

§Virus Threat
Internet users are often plagued by virus attacks on their systems. Virus programs are inconspicuous and may get activated if you click a seemingly harmless link. Computers connected to the Internet are very prone to targeted virus attacks and may end up crashing.

Pornography
Pornography is perhaps the biggest disadvantage of the Internet. Internet allows you to access and download millions of pornographic photos, videos and other X-rated stuff. Such unrestricted access to porn can be detrimental for children and teenagers. It can even play a havoc in marital and social lives of adults.

§Intranet

›Definition

§1. Is a network that belongs to an enterprise and is a accessible only by that enterprise’s employees or authorized users.

(Computer Are your Future: Complete, Catherine LaBerta)

§2. A private network that is set up similar to the Internet and is accessed via a web browser.

(Understanding Computers Today and Tomorrow Comprehensive, Deborah Morley & Charles)

§3. (means within) is an internal network that uses Internet technologies.

(Discovering Computers Complete : Your Interactive Guide to the Digital World, Shelly, Vermaat, Quasney, Sebok, Freund)

§Intranet

›Uses of intranets include groupware applications, such as project management, chat rooms, group scheduling and video conferencing.

›Intranet typically provides e-mail, mailing lists, newsgroup and FTP services accessible only to those within the organization.

›Intranets are intended only for internal use and aren’t accessible from the external Internet unless the user has a registered user name and password.

§Extranet

›1. An intranet that is at least partially accessible to authorized outsiders (suppliers, customers and business partner).

(Discovering Computers Complete : Your Interactive Guide to the Digital World, Shelly, Vermaat, Quasney, Sebok, Freund)

›2. Portion of a company’s network that allows customers or suppliers of a company to access parts of an enterprise’s intranet

(Understanding Computers Today and Tomorrow Comprehensive, Deborah Morley & Charles S.Parker)

›3. Is a private network that connects more than one organizations that use Internet technologies to allow suppliers, customers and business partner limited access to their network.

§Extranet

›Usually accessed via the Internet and they can be used to provide customers and business partners with access to the data they need

Categories	Internet	Intranet	Extranet
Definition	The largest and most well-known computer network, linking millions of computers all over the world.	Is a network that belongs to an enterprise and is a accessible only by that enterprise’s employees or authorized users.	Is a private network that connects more than one organizations that use Internet technologies to allow suppliers, customers and business partner limited access to their network
Types of users	Provide information for public	Provide information for organization employees	Provide information to suppliers, customers and business partner
Usages	Access all kinds of information	Telephone directories, Employee Information, E-mail	Access data, check status place order, send email

the use of internet

§What Can We Use the Internet For?

•View web pages on the WWW (World-Wide Web).

•Sending and receiving e-mail messages.

•Sharing files.

•Communicating using voice (VOIP) and video (video-conferencing).

•Playing multi-player games.

•Listening to streamed music or watching streamed video.

connection to the internet

§Many home and small business users connect to the Internet via high-speed broadband Internet service and dial-up connection.

Dial-Up Connection (Low-Speed)	Broadband Connection (High-Speed)
• Dial-Up Connection	•DSL (Digital Subscriber Line) •Fiber to the Premises (FTTP) •Fixed Wireless •Cellular Radio Network •Cable Internet Service •Wi-Fi •Satellite Internet Service

low speed internet connection

dial up connection

•Dial-Up Connection

Dial-up access takes place when the modem in your computer connects to the Internet via a standard telephone line that transmits data and information using an analog (continuous wave pattern) signal.

high speed internet connection

•DSL (Digital Subscriber Line)	•Provides high-speed Internet connections using regular copper telephone lines.
•Fiber to the Premises (FTTP)	•Uses fiber-optic cable to provide high-speed Internet access to home and business users.
•Fixed Wireless	Provides high-speed Internet connections using a dish-shaped antenna on your house or business to communicate with a tower location via radio signals.
•Wi-Fi (Wireless Fidelity)	•Network uses radio signals to provide high-speed Internet connections to compatible or properly equipped wireless computers and devices.
•Satellite Internet Service	•Provides high-speed Internet connections via satellite to a satellite dish that communicates with a satellite modem.
•Cellular Radio Network	•Offers high-speed Internet connections to devices with built-in compatible technology or computers with wireless modems.

data transfer rate in the internet connection

§What is Data Transfer Rate?

•Data transfer rate, is the speed at which data can be transmitted between devices.

•

•The data transfer rate of a device is often expressed in kilobits or megabits per second, abbreviated as kbps and mbps respectively.

•

•It might also be expressed in kilobytes or megabytes, or KB/sec and MB/sec.

connection to internet

§Components required for successful communications system: Communications Devices and Transmission Media

§Communications Devices:

•Hardware component that enables a computer to send (transmit) and receive data, instructions, and information to and from one or more computers.

Communications Devices
Physical	Channel
Dial-Up Modem	Telephone line
Digital Modems: •DSL Modem (Digital Subscriber Line) •Cable Modem	Digital line
Wireless Modems	Cellular network
Wireless Access Points	Wired network

§Transmission Media:

•Materials or substances capable of carrying one or more signals in a communications channel.

Transmission Media
Physical	Wireless
Cable: •Twisted-Pair Cable •Coaxial Cable •Fiber-Optic Cable	Infrared
	Broadcast Radio (radio signals): •Bluetooth •Wi-Fi •WiMAX
	Cellular Radio: •2G •3G •4G
	Microwaves
	Communications Satellite