WORLD WIDE WEB

WEB BROWSER

- Example :  

 * Mozilla Firefox, Internet Explorer, Opera mini, Safari, and Google Chrome

· WEB PAGE

- Each electronic documents on Web which contains text, graphics, animation, audio and video.

      - Types of web pages :

  

      *  Static ( fixed ) -  A fixed web page where visitors all see the same content.

      * Dynamic ( changing ) - A web pages that allows visitors to customize some of all  

                                                    the viewed  contents

· WEB BROWSER

      - Application software that allows user to access and view Web pages.

      - Purpose : 

      * Bring information resources to the user.

      * Retrieves and displays a starting Web page.

      - Provides link to others related Web pages

      - Process :

      * Downloading -  process of receiving information from a server on the internet

      * Uploading - process of transferring documents, graphics and other objects from a                                 computer  to a server

· WEB SITE

      -  A collection of related web pages and associated items.

· WORLD WIDE WEB

      - Consists of a world wide collection of electronic documents ( web pages )

· WEB SERVER

      - Computer that delivers requested Web pages to your computer

· HOME PAGE

      - First page that a web site display.

WEB ADDRESS

    - Web page that has a unique adress called a URL ( Uniform Resources Locator )      or Web Address

    - A Web browser retrieves a Web page using its Web Adress .

    - Web Address :

* Protocol

* Domain name

* Path

* Web page name

- Example :

 http://www.nps.gov/grsm/planyourvisit/wildlifeviewing.htm

* Protocol - http://

* Domain name - www.nps.gov/

* Path - grsm/planyourvisit/

* Web page name -  wildlifeviewing.htm

- Last component not only web page name, it can be file name.

http://www.kmph.matrik.edu.my/fizik/index.html

* Protocol  - http://

* Domain name - www.kmph.matrik.edu.my/

* Path - fizik/

* Web page name - index.html

- Transfer Protocol :-

*  http://

  - Hypertext Transfer Protocol 

  - A set of rules that defines how pages transfer on the Internet.

 *  https://

  - Hypertext Transfer Protocol Secure

  -  A protocol to provide an encrypted  communication and secure identification of a 

     network web server.

  - Often used for payment transactions on www.

  * ftp://

  - File Transfer Protocol

  - Standard network protocol used to transfer computer files from one host to another 

     host over a TCP-based network, such as the Internet.

WEB PAGE NAVIGATION

'

Navigation Web Pages

• Hypertext

- Link in text based documents.

• Hypermedia

  - Combines text-based links with gaphic, audio and video links

Tab Browsing

 - Allow you to open and view multiple Web Pages in a single Web Browser windows

WEB SEARCHING

- To search specific information, including text, pictures, music and video.

- First step in successful searching is to identify the main idea or concept in topic .

- Types of search tool :

*  Search engine ( keyword search ) - Find information related to a specific topic

* Subject directory ( directory search ) - Classifies Web page in a organized set of categories.

SEARCH  ENGINE

- Program that searches documents for specified keywords and returns a list of the documents where the keywords were found.

- Result  is called as  hit  .

* Web pages

* Articles

* Images

* Audio

* Video and etc

- Hit  :  Any web sites name that is listed as the result of a search.

- Example :

• Google : www.google.com
• MSN : www,search.msn.com
• Yahoo ! : www.yahoo.com

SUBJECT DIRECTORY

- Classifies Web pages in an organized set of categories such as sport or shopping and related subcategories.

- Examples :

* AltaVista

* Yahoo !

* Google

* Excite

- Provide categorized lists of links arranged by subject

- Display a list of subcategories links when click

- Disadvantages : user have difficulty deciding which categories to choose as menus of links presented.

WELCOME TO FARAHSTARSSS  🙆

OVERVIEW OF THE INTERNET

Definition of Network

The Internet is a worldwide collection of networks that links millions of businesses, government agencies, educational institutions, and individuals.

  INTERNET  

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

· ADVANTAGES

-> Software Downloads:

- You can freely download software like utilities, games, music, videos, movies, etc from the Internet.

-> Online Services: 

- Perform all your transactions online. 

- Can book tickets for a movie, transfer funds, pay utility bills. 

- Make a hotel or flight reservation right from your home.

-> E-mail:

- People can sent messages. It is delivered instantly to people anywhere in the world, unlike traditional mail that takes a lot of time.

-> Information resources:

- Can find any information on almost any kind of subject that you are looking for by using search engines like Google, Yahoo, MSN, etc.

· DISADVANTAGES

-> Virus threat:

- Computers attached to Internet are more prone to virus attacks and they can end up into crashing your whole hard disk.

-> Social Disconnect:

- People now only meet on social networks. 

- More and more people are getting engaged with virtual world and drifting apart from their friends and family. 

-> Dangers involved when children using the Internet :

When children talk to others online, they do not realize they could actually be talking to a harmful person. Plus, there are thousands of pornographic sites on the Internet that can be easily found.

-> Theft of Personal information:

Your personal information such as your name, address, credit card, bank details and other information can be accessed by an irresponsible people for their own benefit.

  INTRANET  

An intranet ( intra means within) is an internal network that uses internet technologies.

· ADVANTAGES

->  Commercial or confidential data is kept secure within the organization 

-> Email remain private and may alson be encrypted 

-> High bandwidth. No connectionlimits unlike the internet

-> Reliable. The company will have dedicated IT personnel to keep things running smoothly.

· DISADVANTAGES

-> High financial cost incurred by the company when initially implementing the intranet

-> Connections between an intranet and the Internet potentially compromises security, bye allowing virus infections or system hacking. 

-> Staff needs training to ensure workers know how to use the system effectively.

-> Information overload is another diasadvantages because it reduces productivity.

  EXTERNET  

An extranet is the portion of a company’s network that allows customers or suppliers of a company to access parts of an enterprise’s intranet. 

· ADVANTAGES

- Exchange large volumes of data using electronic data interchange (EDI)

- Share product catalogs exclusively with trade partners

- Collaborate with other companies on joint development efforts

- Jointly develop and use training programs with other companies

· DISADVANTAGES

- Extranets can be expensive to implement and maintain within an organization (e.g., hardware, software, employee training costs), if hosted internally rather than by an application service provider.

- Security of extranets can be a concern when hosting valuable or proprietary information.

CLASSIFICATION OF NETWORK 

( LAN , WAN & MAN )

• LAN ( Local Area Network )

- Network that connects computers and devices in a limited geographical area.

• WAN ( Wide Area Network )

- Network that covers a large geographic area (such as a city, country, or the world) using a communications channel that combines many types of media such as telephone lines, cables, and radio waves.

• MAN ( Metropolitan Area Network )

- High-speed network that connects local area networks (LAN) in a metropolitan area such as a city or town

CRITERIA	LAN	MAN	MAN
AREA OF COVERAGE
	Network cover limited geographical area such as closely positioned group of buildings network , network at home, network inside computer laboratory and network in office building .	A high speed network that connects Local Area Networks in a Metropolitan Area such as a cities or town.	Network cover large geographical area such a countries , the  continents or the world
NETWORK SIZE	Small size ( in a building)	Larger size ( in a cities or campus)	Largest size (different states or countries)
SPEED	Fastest in data transferring and access time	Slower in data transferring and access time	Slowest in data transferring and access time
EXAMPLE	Network inside the lap	Surveillance system	Car Navigation System
COMMUNICATION DEVICES	Connected using modems, hubs, switch , router	Connected using modems, hubs, switch , router	The connection is made via satellite communication link or via internet
COST	Less costly setup and maintenance	More costly setup and maintenance	Costliest setup and maintenance
OWNERSHIP	Private	Private	Not owned

→ NETWORK TOPOLOGY  ←

DEFINITION 

👉  NETWORK TOPOLOGY   👈

Layout of the computers and devices in a communications network.

👉  PHYSICAL TOPOLOGY   👈

The arrangement of a cabling is the physical topology

👉   LOGICAL TOPOLOGY   👈

The path that data travels between computers on a network is the logical topology.

STAR TOPOLOGY

 DEFINITION

All the computers and other devices on the network connect to a central device thus forming star.

ADVANTAGES 

• If one device fails, only that device is affected.
• Devices can be added or removed from network with no disruption.
• Easy to troubleshoot and isolate problem.

DISADVANTAGES

• If the hub or switch fails, the entire network will be inoperabled.
• Requires more cables than most of the other topologies.
• More expensive because of the cost of hub/switch. 

BUS TOPOLOGY

DEFINITION

A bus network consists of a single central cable (backbone), to which all computers and other devices connect.

ADVANTAGES

• Inexpensive and easy to install.
• Other devices can be attached or detached without disturbing the network.
• Failure of one device usually does not affect the rest of the network.

DISADVANTAGES

• There might be disruption when computer or other devices are added or removed.
• The break in the main cable(backbone) will prevent all systems from accessing the network.
• It is difficult to identify the problem if the entire network Shut down.

RING TOPOLOGY

DEFINITION

On a ring network, a cable forms a closed loop (ring) with all computers and devices arranged along the ring.



ADVANTAGES

• Transmission of data is simple as packets travel in one direction only.
• Cabel faults are easily located, making troubleshooting easier.
• All devices in ring topolgy share the network resources fairly

DISADVANTAGES

• A failure in any cable 
• or device breaks the 
• loop and can take 
• down entire 
• network.
• Data packets must pass through every computer, thus make it slower.
• More difficult to install than a bus network.

WHAT IS NETWORK ARCHITECTURE ?

NETWORK ARCHITECTURE 

• The configuration of computers, devices and media on a network.

CATEGORIES OF NETWORK :-

• PEER TO PEER NETWORK
• CLIENT/SERVER NETWORK

PEER TO PEER NETWORK

• A simple, inexpensive network that typically connects fewer  than 10 computers.
• Each computer has equal responsibilities and capabilities. 
• Allows users to set up a peer-to-peer network.
• Each computer stores files on its own storage devices.
• All computers on the network share any peripheral device(s) attached to any computer. 
• Ideal for very small businesses and home user
• Directly available without the need for central coordination by servers or stable hosts.

CLIENT/SERVER NETWORK

• One or more computers act as a server, and the other computers on the network request services from the server.
• Server : host computer, controls access to the hardware, software and provides a centralized storage area for programs, data and information.
• Clients  rely on the server for its resources.
• Client computer sends a resource or process request to the server over the network connection
• Server can manage several clients simultaneously
• Web server serves many simultaneous users with Web page and or website data.

CATEGORIES	CLIENT/SERVER NETWORK	PEER TO PEER NETWORK
DEFINITION	One or more computers act as a server on the network request services from the server.	Each computer equal responsibilities and capabilities, sharing hardware, data, or information
SIZE	For medium and large network	For small network fewer than 10 computers.
OPERATING SYSTEM	Needs a specific operating system such as Windows Server 2008.	Does not need a specific operating system.
TRAINING	Needs training	Does not need training
SET UP	More difficult to set up	Easy to set up
INSTALLATION	More expensive to install	Less expensive to install
IMPLEMENT	Big corporations or organizations with high security data	Small businesses and home users