Class 10 Session 2 Networking fundamentals | web application notes

Hello friends we come back with New unit Web Application with Session 2 Networking Fundamentals, in this chapter we were learn About network types and www modem wifi dial up ect Let start exploring each and every topic related to Networking Fundamentals.

A computer network is a collection of computers and other hardware components interconnected by communication channels (cables or satellites) that allow sharing of resources and information. this session introduces you to the basic fundamental concepts of networking and internet and using different types of internet connection. Networks are designed using the following architecture: 

Peer-to-peer (P2P) Architecture: networks in which all computers have an equal status are called peer to peer networks. Generally in such a network each terminal has an equally competent CPU.

Client-Server Architecture: networks in which certain computers have special dedicated tasks, providing services to other computers (in the network) are called client server networks. the computer(s) which provide services are called servers and the ones that use these services are called clients. 

Types of networks there are two major types of network 

Local Area network (LAN) and Wide Area network (WAN). 

Local Area Network 

A local area network (LAn) is one which connects computers and devices in a limited geographical area such as home, school, computer laboratory, office building, or closely positioned group of buildings. Usually local area networks offer very high speeds and are used for connecting computers and peripherals such as printers, scanners, etc. 

Wide Area Network 

A wide area network (WAN) is one which covers a broad area (i.e., any network that links across metropolitan, regional, or national boundaries). the internet is the most popular WAN, and is used by businesses, governments, non-profit organizations, individual consumers, artists, entertainers, and many others. internet the internet is a global system of interconnected computer networks that use the standard internet protocol suite to serve billions of users worldwide. it is a network of networks that consists of millions of private, public, academic, business, and government networks. internet is one of the most useful technologies of modern times which help us in our daily, personal and professional life. internet is widely used by students, educational institutes; scientist and professionals to gather information for research and general information. Businesses use the Internet to access complex databases such as financial database. 

The Internet is the largest encyclopaedia for all age groups. the internet helps in maintaining contact with friends and relatives who live across different locations via internet chatting systems and email software. internet is also becoming a major source of entertainment for the general public. 

Metropolitan Area Network (MAN) Metropolitan Area Network (MAN) is an extended form of LAN which covers a larger geographical area like a city or a town. Data transfer rate in MAN also ranges in Mbps, but it is considerably less as compared to LAN. Cable TV network or cable based broadband internet services are examples of MAN. This kind of network can be extended up to 30-40 km. Sometimes, many LANs are connected together to form MAN,

World Wide Web 

World Wide Web (abbreviated as WWW or W3, commonly known as the Web), is a system of interlinked hypertext documents accessed via the internet. With a web browser, one can view web pages that may contain text, images, videos, and other multimedia, and navigate between them via hyperlinks.information is stored on web servers referred to as web pages are retrieved by using a web browser such as Firefox on the local computer. 

A Web Browser is a software used to view Web sites and acts as an interface between the user and the World Wide Web. A Web server is a computer that stores web sites and their related fles for viewing on the Internet. Some of the advantages associated with networking are: 

• Data Sharing: One of the most important uses of networking is to allow the sharing of data. Users can send text files, spread sheets, documents, presentations, audio files, video files, etc. to other users. 
• Hardware Sharing: Hardware components such as printers, scanners, etc. can also be shared. For example, instead of purchasing 10 printers for each user, one printer can be purchased and shared among multiple users thus saving cost.
• internet Access Sharing: You can purchase a single internet connection and share it among other computers in a network instead of purchasing multiple internet connection for each computer. this is very commonly found in internet café (browsing centres), schools, colleges, companies, etc. 
• Usage of network based applications: Such as web browsers, email clients, chat application, audio & video calling, etc is another advantage.

Getting access to the internet to use the internet, you need an internet connection. internet connections are provided by internet Service Providers such as Bharat Sanchar nigam Limited (BSnL), Airtel, MtS, Vodafone, tata Docomo, etc. 

Internet Service Provider 

An Internet service provider (ISP) is an organization which provides you with access to the Internet via a dial-up (using modem) or direct (hard wired) or wireless connection. Choosing connectivity depends on the availability of a particular technology, speed and connection type in your area. Usually small and medium business users, home users use connectivity types such as DSL, cable modem, dial-up, broadband wireless, WiMAX or 3G. Medium to large business users or customers with more demanding requirements may use high speed connectivity such as DSL (High Speed), iSDn, etc. 

Modem Á modem is a device that converts digital computer signals into a form (analog signals) that can travel over phone lines. it also re-converts the analog signals back into digital signals. the word modem is derived from its function MOdulator/DEModulator.

Some of the commonly used internet connectivity are: 

Dial-up: 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) via telephone lines using a device called MODEM. Users dial a particular number provided by the iSP and gain access to the internet. Dial-up connections are extremely slow and in most cases, it is replaced by a high speed connection such as DSL or Cable Modem. 

DSL: Digital subscriber line(DSL) provide internet access by transmitting digital data over wires of a local telephone network. DSL service is delivered along with wired telephone service on the same telephone line. On the customer premises, a DSL flter removes the high frequency interference, enabling simultaneous use of the telephone and data transmission. For using a DSL connection, you need a DSL modem and a subscription. 

Cable internet Access: Cable internet Access is a form of broadband internet access that uses the cable television infrastructure. Cable internet Access is provided through existing cable tV networks; this is similar to DSL that is provided over existing telephone lines. 

3G: 3G, short for 3rd Generation is a set of standards used for mobile devices and mobile telecommunication services and networks. High-Speed Downlink Packet Access (HSDPA) is 3G mobile telephony communications protocol that allows higher data transfer speeds and capacity. if support for 3G is available on your mobile phone, you can subscribe to the 3G connectivity with your iSP in order to get high speed internet connection on your phone.

WiMAx: WiMAX (Worldwide interoperability for Microwave Access) is a wireless communications standard designed to provide mobile broadband connectivity across cities and countries through a variety of devices. WiMAX is a long range system, covering many kilometres and is typically used where DSL or Cable Internet Access cannot be used; this could be diffculty in laying out cables for home or offces located in remote locations but need access to the Internet. 

Wi-Fi: Wi-Fi is a popular technology that allows an electronic device such as computers or mobile phones to exchange data wirelessly over a network, including high-speed internet connections. Wi-Fi devices such as personal computer, smartphones, video game console, etc. can connect to a network resource such as internet through a device called the Wireless Access Point (WAP). WiFi is used where cables cannot be run (such as old buildings, outdoor areas) to provide network and internet access. Wi-Fi can also be used where users require mobile connectivity. Wi-Fi connectivity is used in home & offces, hotels, college & school campus typically for Internet Access. Shopping malls, coffee shops, resorts mostly offer free or paid Wi-Fi access to the internet for their customers.

Data transfer on the internet Having talked of data transfer and the internet, have you ever wondered how sitting in one corner of the world, you get information from another distant area in a few seconds? in very simple language, let’s see what happens to a piece of data, say a Web page, when it is transferred over the internet: 

• The data is broken up into bits of same sized pieces called packets.
• A header is added to each packet explaining where the data has come from, where it should end up and where it fts in with the rest of the packets.
• Each packet is sent from computer to computer until it fnds its destination. Each computer on the way decides where next to send the packet. All packets may not take the same route.
• At the destination, the packets are examined. if any packets are missing or damaged, a message is sent asking for them to be re-sent. this continues until all packets have been received intact.
• The packets are now reassembled into their original form. All this done in seconds!