User:MLRAVICHANDRA/sandbox

efinition of terms i) Network A colection of independent entities that are arranged in such a manner to exchange data, information or resources e.g Road networks, telephone networks. ii) Computer networks A collection of computers linked together using transmission media for the purpose of communication and resource sharing

iii) Transmission Media is a physical and non-physical link between two or more computers and in which a signal can be made to flow from source to destination

iv) Resource Sharing Is the sharing of the resources that are attached to the network for access by users eg file, printers, data, application programs etc

v) Data Communication A process of transmitting data signal from one point to anothe through the network

vi) Telecommunication The communication i.e. transferring of data and information over significant distances is known as telecommunication. Image result for computer networking Advantages of computer network are:

Data and software of computer can be shared with other computer on the network. Only the authorized user of a network can use the facilities of the network. Computers on the network can communicate with each other. The disadvantages of computer network are:

Data and information may be stolen by computer hackers if the security of network is not reliable. If any computer in a network gets affected by computer virus, there is high chance of spreading computer viruses on the other computer. Computers on the network have to depend on the server computer for resources. This sharing of information may leak the privacy of other clients. Explain how computer network reduce expences in an office. - Computer Networks can allow businesses to reduce expenses and improve efficiency by sharing data and common equipment, such as printers, among many different computers. At the same time, the network may be connected through cables, telephone lines, infrared beams etc, which is cheaper and helps to reduce the expenses.

TERMS USED IN DATA COMMUNICATION i) Data siganal Is a voltage signal level in the circuirt which represents the flow of data. This can be either Analog or Digital in nature ii) Signal mgnaodulation and Demodulation Is a process of converting data signal to and from a form that is suitable for transmission over a transmition medium. MODEM - Converts digitl signal by superimposing it on an analog carrier signal which is trnsmitted over analog telephone line. A process known as Modulation A modem at the receiving end converts the analog signal into digital form a process called Demodulation.

iii) Multiplexing Is a process of sending multiple data signals over the same medium e.g a wire conductor can carry several data signal either simultenously or at differenet times. Demultiplexing A preocess of seperating the multiplexed signals at the receiving end.