The World Wide Web

Web Browser

A web browser (commonly referred to as a browser) is a software application for retrieving, presenting and traversing information resources on the World Wide Web. An information resource is identified by a Uniform Resource Identifier (URI/URL) that may be a web page, image, video or other piece of content.[1] Hyperlinks present in resources enable users easily to navigate their browsers to related resources.

Although browsers are primarily intended to use the World Wide Web, they can also be used to access information provided by web serversin private networks or files in file systems.

The most popular web browsers are Chrome, Edge (preceded by Internet Explorer), Safari, Opera and Firefox. 

Web Address

A web address, also known as a URL (uniform resource locator), is an Internet or intranet name that points to to a location where a file, directory or website page is hosted. Website addresses can represent the home page of a web site, a script, image, photo, movie or other file made available on a server for viewing, processing or download. They can also be embedded into the code of web pages in the form of hyperlinks to direct the user to other locations on the Internet.

Web Address consist of :

• protocol
• domain name
• web path
• web page name

example of web address

Web Pages Navigation

Web navigation refers to the process of navigating a network of information resources in the World Wide Web, which is organized as hypertext or hypermedia. The user interface that is used to do so is called a web browser. We can surf the web by using links to explore the web. The links can be text or image. If you surf the web by using links(texts link), the text may be underline in a different color from the other texts. The color of the link will change once the link has been visited.

Most web pages contain hypertext or hypermedia links

Web Searching

A primary reason that people use the Web is to search for specific information, including text, pictures, music and video. The first step in successful searching is to identify the main idea or concept in the topic about which you are seeking information.

Subject Directory

Search Engine 

The Internet Address

What is IP Address ?

• A number that uniquely identifies each computer or device connected to the Internet.
• IP addresses are also referred to as IP numbers and Internet addresses.

IP Usage.

• A way to find specific server or computer on the Internet or a network.
• Provide identify to a computer in a network.
• Identify for particular devices/machine on a particular network
• allows transfers of files and e-mail.

IP Structure.

• IP addresses usually consists of four groups of number each separated by a period
• The number in each group is between 0 to 255.
• It is 32 bit long , each group is 8 bits long and commonly in decimal.
  

Ip v6 vs Ip v4

The Internet Service Provider

Internet Services Provider.

A company that provide Internet connections and services ti individuals and organizations.

Access Provider.

A business that provides individuals and organizations access to the Internet for free or for a fee.

RESPONSIBILITIES OF AND ISP.

Providing and maintaining a connection to the Internet.

Support the hardware and software needed to service that connection.

To protect their site and network from external threats such as viruses,hacker attacks and other illegal activities.

Provide 24-hours customers service and technical support.

EXAMPLE OF INTERNET SERVICE PROVIDER (ISP).

ISP : TMNET

PRODUCT : Streamyx , UniFi , TM Hotspot

Different between Internet Connections

There are many ways a personal electronic device can connect to the internet. They all use different hardware and each has a range of connection speeds. As technology changes, faster internet connections are needed to handle those changes. I thought it would be interesting to list some of the different types of internet connections that are available for home and personal use, paired with their average speeds.

There are two different types of connection which is :

1. Dial-up connection

2. Broadband internet connection / direct connection

DIAL-UP CONNECTION

Dial-up Internet access is a form of Internet access that uses the facilities of the public switched telephone network (PSTN) to establish a connection to an Internet service provider (ISP) by dialing a telephone number on a conventional telephone line. The user's computer or router uses an attached modem to encode and decode information into and from audio frequency signals, respectively.

CONVENTIONAL DIAL UP

(to connect to the Internet, your computer dials its modem and connects to a modem attached to a computer belonging to your ISP.)

PC has to dial via a phone line to connect

Characteristics of Conventional dial-up:

 Slower, but cheaper

 Ties up phone lines

 Relatively secure from hackers

 Example :- TMNet

ISDN ( INTERGRATED SERVICE DIGITAL NETWORK)

also transfer data over ordinary telephone lines

Typically uses two phone lines to transfer data

ISDN requires a special ISDN modem

Characteristics of ISDN:

 Faster, but pricey

 Doesn’t tie up phone line

 Used by businesses and individuals

BROADBAND INTERNET CONNECTION / DIRECT CONNECTION

Broadband Internet service truly is the most used form of Internet access because of its high access speeds; it is offered in four different forms, DSL (or Digital Subscriber Line), also fiber-optic, cable, and satellite. The old dial-up connection is the only non-broadband internet service available, and even though it is cheaper, most Internet users are moving towards the faster broadband Internet connection.

TYPES	DESCRIPTION
DSL	Broadband delivered over telephone lines
Fiber to the Premises	Delivers over fiber-optic cabling all the way to the building
Fixed Wireless	Uses radio transmission towers rather than satellites
Cellular Radio Network	Offers high-speed Internet connections to devices with built-in compatible technology or computers with wireless modem
Cable Internet Service	Provides high-speed Internet access through the cable television network via a cable modem
Wi-Fi	Provide high-speed Internet connections to compatible or properly equipped wireless computers and devices
Satellite Internet Services	Provides high-speed Internet connections via satellite.

Overview Of the Internet

What is Internet?

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

ADVANTAGE & DISADVANTAGE OF INTERNET

                                       WHAT IS INTRANET?

An intranet is a private network that is contained within an enterprise. It may consist of many interlinked local area networks and also use leased

WHAT IS EXTRANET?

Portion of a company's network that allows customers or suppliers of a company to access parts of an enterprise's intranet

Network Topology

A network topology refers to the layout of the computer in a communication network. It refers to both the physical and logical layout of a

network.

Physical topology	Logical topology
The arrangement of a cabling is the physical topology	The path that data travels between computers on a network is logical topology

There are 3 commonly used network topologies 



1. Bus network topology

Advantages and disadvantages of Bus topology

Advantages	Disadvantages
It works well when you have a small network	It can be difficult to identify the problems if the whole network goes down
It is the easiest network topology for connecting computers or peripherals in a linear fashion	It can be hard to troubleshoot.Individual device issue
It requires less cable length than a star topology	If a main cable is damaged,the network fails or splits into two

2.Star network topology

Advantages & disadvantages of star topology

Advantages	Disadvantages
If one device fails.the other will not be affected	If the hub/switch fails.Entire network will be inoperable
Device can be added or remove without any distruption	Require more cable than other topologies
Easy to troubleshoot and isolate problem	Most expensive because of the cost of the hubs/switch

3. Ring network topology

Advantages & disadvantages of Ring Topology

Advantages	Disadvantages
All data flows in one direction,reducing the chance of packet collision	All data being transferred over the network must pass through each workstation on the network,which make it slower than a star topology
A network server is not needed to control network connectivity between each workstation	The entire network will be impacted if one workstation shuts down
Data can transfer between workstations at high speed	The hardware needed to connect each workstation to the network is more expensive

Network Architecture

Network Architecture is the configuration of computers, devices and media on a network. There are two types of network architecture that is peer-to-peer network and client/server network

Category	Client/ server	Peer-to-peer
Definition	One or more computers act as a server, and the other computers on the network request services from the server.	Each computer, called a peer, has equal responsibilities and capabilities, sharing hardware (such as a printer), data, or information with other computers on the peer-to-peer network.
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
Implementation	Big corporations or organizations with high security data	Small businesses and home users

client server network

peer-topeer network

Computer Network

What Is Network?

A network is a collection of computers and devices connected together via communications devices and transmission media.

Communication Devices

A communications device is any type of hardware capable of transmitting data, instructions, and information between a sending device and a receiving device.

Dial-up Modem A communications device that can convert digital signals to analog signals and analog signals to digital signals, so that data can travel along an analog telephone line.
Digital Modem (ISDN, DSL and Cable Modem) A communications device that sends and receives data and information to and from a digital line.
Wireless Modem Some mobile users have a wireless modem that uses the cell phone network to connect to the Internet wirelessly from a notebook computer, a smart phone, or other mobile device
Network Card Sometimes called a network interface card, is a communications device that enables a computer or device that does not have built-in networking capability to access a network.
Wireless Access Point A central communications device that allows computers and devices to transfer data wirelessly among themselves or to transfer data wirelessly to a wired network . *Wireless access points have high-quality antennas for optimal signals.
Router A communications device that connects multiple computers or other routers together and transmits data to its correct destination on a network.
Switch A connection device similar to a hub but more sophisticated, including functionality that allows it to control and manage data transmissions.
Hub A connection device that allows multiple connections to the network.

Transmission Media

Transmission media is materials or substances capable of carrying one or more signals in a communications channel. There are two types of transmission media that is Physical Transmission Media and Wireless Transmission Media

Advantage & disadvantage of network 

Advantage	Disadvantage
Easy to communicate	Expensive to build
Easy to share data & Information	Security Threats
Can share information	Bandwith issue