What do you mean by data communication? Write shortly about the main components of a data communication system.

What is data representations? Write shortly about different modes of data flow.

When two or more devices connected through links, there is a term called "physical topology". So what do you mean by this term? Write the advantages and the disadvantages of those topologies.

For n devices in a network, what is the number of cable links required for each of those topologies?

What do you mean by switching? Write the advantages and the disadvantages of different switching techniques.

What do you mean by network models and protocol layering?

Write shortly about the responsibilities of different layers of the OSI model.