Basic networking concepts

 Types of guided media :- 

1.Twisted pair cable :- 

It consists of 2 separately insulated conductor wires wound about each other. Generally several such pairs are bundled together in a protective sheath. They are the most widely used transmission media. twisted pair  is of two Types;


It has an outer plastic covering containing 2 parallel conductors each having a separate insulated protection cover.
Coaxial cable transmits in two.modes(cable bandwidth is sprit separate ranges).cable T.Vs and analog television network widely used coaxial cable.

Advantages:-
  •  Higher bandwidth.
  • Better noise immunity.
  • Easy to install and expand.
  • Inexpensive.

Disadvantages:-

  • It uses the concept of reflection of light through a core made up of glass or plastic. The core is surrounded by a less dense glass or plastic covering called the cladding.it is used for transmission of large volumes of data.

Advantages:-

Disadvantages:-
  • Difficult to install and maintain.
  • High cost.


Cryptography is used to secure and protect data during communication.it is helpful to prevent unauthorised person and group of users from accessing any confidential data.
Encryption and decryption are two essential functionality of cryptography.


Encryption is a process which transforms the original information into an unrecognisable form.this new form of the message is entirely different from the original message.that's why a hacker is not able to read the data as sender use an encryption algorithm.encryption is usually done using keh algorithms.
Data is encrypted to make it safe from stealing.however,many know companies also encrypt data to keep their trade secret from their competitors.


Decryption is a process of converting encoded/encrypted data in a form that is readable and understood by a human or a computer.this method is performed by un-encrypting the text manually or by using keys used to encrypt the original data.

Need for networking:-

Resource sharing:- connecting computers through networking allows us to share hardware and software resources.Example of hardware resources include peripherals (for example, printers and scanners) ,CPU,and memory. 
Example of software resources include system and application software,and files that may include text,audio,and video content.

Communication :- connecting computers through a network facilitates exchange of information amongst the nodes in the network.

Access to remote database:- it is easy for an average person to access any remote database,say for example airline reservation and thereby book tickets.
Likewise databases of trains , online universities,hotels ,etc.

Requirement of a network:-

Every network includes:

Network terminologies:-
1) Nodes:- A computer becomes a node (also called a workstation)as soon as it is attached to a network.eacb user on a network works on a workstation.if there are no nodes there would be on network.

2) Server:- A computer that facilitates sharing  of data , software and hardware resources on the network is known as the server.a network can have more than one server also.
Each server has a unique name by which it is identified by all the nodes on the network.
Servers can be of two types:

  1. Dedicated servers:- These are generally used on big network installation where one computer is reserved for the server's job.it helps all nodes access data, software and hardware resources.
  2. Non-dedicated servers:- In small networks,a workstation can double up as a server.these servers are known as Non-dedicated servers.the small networks using such as server are known as peer to peer network.

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