Questions What do you mean by Network?

Physical (Layer 1)

OSI Model, Layer 1 conveys the bit stream - electrical impulse, light or radio signal — through the network at the electrical and mechanical level. It provides the hardware means of sending and receiving data on a carrier, including defining cables, cards and physical aspects. Fast Ethernet, RS232, and ATM are protocols with physical layer components.

7. 
   Describe Hub, Switch and Router?
   

Hubs, switches, and routers are all computer networking devices with varying capabilities. Unfortunately, the terms are often misused.

Hubs, switches, and routers are all devices that let you connect one or more computers to other computers, networked devices, or even other networks. Each has two or more connectors called ports, into which you plug the cables to make the connection.

Varying degrees of magic happen inside each device — and therein lies the difference.

• 
  Hubs are “dumb” devices that pass on anything received on one connection to all other connections.
  
• 
  Switches are semi-intelligent devices that learn which devices are on which connection.
  
• 
  Routers are essentially small computers that perform a variety of intelligent tasks.