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The basics of internet, intranet, email or audio and video conferencing can be better understood if we understand first the computer network. A computer network is the backbone of the internet and related activities.
Basics of Internet
A network is simply an interconnection of one or more computers for the purpose of sharing information and resources (printers, storage devices, and application).
Computer Networks means an interconnected set of an autonomous system that permits distributed processing to information.
|UNIT – IV: Information and Communication Technology (ICT) (Click below to read the study notes)
Five components of Networking
- Sender Computer
- Sender equipment (Modem)
- Communication Channel (Telephone Cables or wireless device)
- Receiver Equipment (Modem)
- Receiver Computer
Types of Network
Classification Based on Geographical Coverage:
Local Area Network (LAN): A local area network is a relatively smaller and privately-owned network with a maximum span of 10 km.
Metropolitan Area Network (MAN): MAN is defined for less than 50 Km and provides regional connectivity within a campus or small geographical area.
Wide Area Network (WAN): A wide Area Network (WAN) is a group Communication Technology provides no limit of distance.
Classification Based on Channel
1. Point to Point Network: When a packet is sent from one router to another intermediate router, the entire packet is stored at each intermediate router, stored there till the output line is free and then forwarded. A subnet using this principle is called point to point or packet-switched network.
Topologies for a point to point Subnet
- Star: Each device has a dedicated point to point link only to a central controller, usually called a
- Tree: A tree topology is a variation of a
- Ring: Each device has a dedicated point to point line configuration only with the two devices on either side of
- Bus: One long cable act as a backbone to link all the devices in the
2. Broadcast Networks: Broadcast networks have a single communication channel that is shared by all the machines on the network.
An intranet can be an excellent method for sharing organizational information and creating internal communication channels. An intranet is an ideal way to communicate in a secure environment. An intranet provides a way to communicate with a common technology.
Intranets allow organizations to make effective use of their digital organizational information resources, offering interoperability, ease of use, security, and cost-effectiveness.
- A collection of resources to which only internal users have access.
- A private network inside an organization, similar to the Internet, but which is for internal use only, and is not accessible to the public.
- Users of an Intranet can exchange electronic mail (email), send files (FTP), browse web (WWW) pages, and connect to any other computer. Just like the normal internet, however, only people within an organization can use the intranet.
- Intranets are often separated from the Internet by using a firewall.
- Organizations use Intranets to manage projects, provide employee information, distribute data and information, internal communication
Advantages of Intranet
- Data can be stored centrally
- Allows easier maintenance of data
- Web-based interface for access o common technology for communication
- Ability to access from anywhere in the world
The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite (TCP/IP) to link several billion devices worldwide. It is also known as “network of networks” that consists of millions of private, public, academic, business, and government networks.
Various applications of internet
- Exchange messages using e-mail (Electronic mail).
- Transfer files as well as software.
- Browse through information on any topic on the web.
- Communicate in real-time (chat) with others connected to the Internet.
- Search databases of government, individuals and organizations.
- Read news available from leading newsgroups.
- Send or receive animation and picture files from distant places.
- Set up a site with information about your company’s products and services.
The World Wide Web commonly known as the Web or “www” developed by Tim Berners – Lee in 1989, is a system of interlinked hypertext documents that are accessed via the Internet. These multimedia pages are ever-changing.
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.
Ex. WorldWideWeb (First Web Browser), Netscape, Internet Explorer, Opera, Mozilla Firefox, Safari (Apple), Google Chrome, UC Browser etc.
Various Features of a Web Browser
A web browser has the following features:
Menu bar: The menu bar, located at the very top of the screen, can be accessed using the mouse. Actions that are in black can be performed, while actions that cannot be performed will be in grey or lightened.
Toolbar: The toolbar is located at the top of the browser; it contains navigational buttons for the Web. Basic functions of these buttons include:
|Home||Opens or returns to starting page|
|Back||Takes you to the previous page|
|Forward||Takes you to the next page|
|Prints current page|
|Stop||Stops loading a page|
|Reload||Refresh/redisplays the current page|
|Search||Accesses search engine|
Location bar: The location bar, below the toolbar, is a box labelled “Location,” “GoTo,” or “Address.” You can type in a site’s address and press the Return or Enter key to open the site.
Status bar: The status bar is located at the very bottom of the browser window. You can watch the progress of a web page download to determine if the host computer has been contacted and text and images are being downloaded.
Scroll bar: The scroll bar is the vertical bar located on the right of the browser window. You can scroll up and down a web page by placing the cursor on the slider control and holding down the mouse button.
A website is a set of related web pages served from a single web domain.
Uniform Resource Locator abbreviated as URL is the Address for web sites. Most of them begin with HTTP (HyperText Transfer Protocol), followed by a colon and two In most web browsers, the URL of a web page is displayed on top inside an address bar. An example of a typical URL would be “http://www.scholarify.in“.
A Hyperlink is a reference to data that the reader can directly follow either by clicking or by hovering or that is followed automatically.
Downloading means to receive data to a local system from a remote system, or to initiate such a data
Uploading refers to the sending of data from a local system to a remote system such as a server or another client with the intent that the remote system should store a copy of the data being
Electronic Mail (e-mail)
Electronic Mail (e-mail) was invented by “John Von Neumann”. Electronic Mail transfers the data from one system to another system in the form of messages (test), pictures (images), multimedia messages.
An e-mail address normally consists of three parts.
- Name of the User
- “@” Sign
- It comes after @ sign and it is the name of the DNS.
Example: scholarify @ gmail .com
Scholarify (user name)
Gmail.com (Domain name System)
In the e-mail window, you can find “folder Pane” at the left side of the window. It has a set of folders named as Composed mail, Inbox, Out Box, Sent Items, Drafts, Trash, Spam etc.,
- Inbox: used to store incoming
- Sent Items: used to store mail that has already been
- Deleted Items (Trash): used to store deleted mail up to 30
- Draft folder: use to store mail that is not yet
- Spam: used to store the unsolicited bulk e-mail up to 30
- Compose Mail: use to create a new
When you start to compose an e-mail, the following activities have to do:
- To: To type the e-mail address of the person to whom you want to send a mail-in this box.
- Subject: To type a few words about the subject of the letter you want to write.
- CC (Carbon Copy): To type the e-mail address of the other recipients in this box, each address is separated by a comma (,). When you complete the mail and click the “Send” button, then the mail will automatically be sent to all the recipients. Here, all the recipients will know who the other recipients are.
- BCC (Band Carbon Copy) or (Blind Curtsey Copy): If you don’t want them to know who else have received copies, you can type the addresses in the BCC text, In this case, only you (the sender) will know the identity of all the recipients of mail.
- Reply: You can send your reply using the same The subject box will have the same subject, but with the words “Re:” before it.
- Forward: You can send the forward message using the same The subject box will have the same subject, but with the words “Fwd:” before it.
- An email attachment is a computer file sent along with an email message. One or more files can be attached to any email message and be sent along with it. The first email was sent by Ray Tomlinson to himself in 1971.
- The Drafts folder retains copies of messages that you have started but is not yet ready to send.
Important points of e-mail
Hotmail, a free e-mail service provided by Microsoft which was established in 1995 was co-founded by an Indian American entrepreneur Sabeer Bhatia along with Jack Smith in July of 1996.
An Internet Protocol address (also known as an IP address) is a numerical label assigned to each device (e.g., computer, printer) participating in a computer network. It acts as an identifier for a computer. It is a unique address for every computer.
Top-level domain: Each part of a domain name contains certain information. The first field is the hostname, identifying a single computer or organization. The last field is the top-level domain, describing the type of organization and occasionally country of origin associated with the address.
For e.g. – .com – Commercial, .edu – Educational, .org – organisation, .net – Network, .in – India etc.
- Transmission Control Protocol (TCP)
- User Datagram Protocol (UDP)
- Internet Protocol (IP)
- Post Office Protocol (POP3)
- HyperText Transfer Protocol (HTTP)
- File Transfer Protocol (FTP)
- Internet Control Message Protocol (ICMP)
- Internet Message Access Protocol (IMAP)
Audio and Video Conferencing
Audio conferencing is where two or more people in different locations use technology like a conference bridge to hold an audio call. Audio conferencing is different from a traditional phone in that all participants dial into a central system that connects them instead of directly dialling each other. Audio conferencing aims at achieving communications and collaboration simultaneously. Many audio-conferencing products may also come with online collaboration elements standard or optional, like screen-sharing capabilities, to further enhance the value of audio meetings.
Video conferencing is a technology-enabled type of meeting where two or more people, in different geographic locations, conduct live visual conferences through the internet for the purpose of communicating and collaborating. Video conferencing software (or hardware) enables transmission of high-quality audio, static images—sometimes full-motion video images—and text-based messages between multiple locations. As long as they have a webcam (an embedded camera), a desktop, laptop or mobile phone device can be used for video conferencing.
Web Conferencing (Internet Based)
Web Conferencing is an online service by which you can hold live meetings, conferencing, presentations and training via the internet (particularly on TCP/IP connections). Users can connect to the conference either by telephone or using the computer’s speakers and microphone through a VoIP connection.
Web conferencing usually allows real-time point-to-point communication as well as multitask communications from one sender to many receivers in separate locations. Depending on the service, either an application (additional software) is downloaded and installed or a web-based application is launched in the attendee’s browser.
Web conferencing software or website makes collaboration easier, with the following common features:
- Whiteboard: which allows you or your attendees to draw or annotate a shared screen.
- Screen sharing, so you can share with other conference attendees something on your local workstation.
- Audio conferencing, for times when an audio-only call is sufficient.
- Webinars, which allows you to present to a group while maintaining control over who can contribute (i.e., every attendee can hear you, but no one else can present during the session).
- Online meetings, which are basically scheduled conferences that include the ability for you to send out invitations and block off time on the requested attendees’ calendars.
- Mobile access or apps, so that people can participate even when on the go.
- Real-time chat, which allows people to text type during the conference. This is useful for sharing links during discussions and making notes.
Most popular Audio and Video Conferencing Software or websites: