What is Network?
A network is a set of devices (often referred to as nodes) connected by communication links. A node can be a computer, printer, or any other device capable of sending and/or receiving data generated by other nodes on the network.
In short we can say that network is interconnection of devices that can communicate.
Most networks use distributed processing, in which a task is divided among multiple computers. Instead of one single large machine being responsible for all aspects of a process, separate computers (usually a personal computer or workstation) handle a subset.
Network Criteria: A network must be able to meet a certain number of criteria. The most important of these are performance, reliability, and security.
- Performance:-Performance is often evaluated by two networking metrics: throughput and delay. We often need more throughput and less delay. However, these two criteria are often contradictory. If we try to send more data to the network, we may increase throughput but we increase the delay because of traffic congestion in the network.
- Reliability:- In addition to accuracy of delivery, network reliability is measured by the frequency of failure, the time it takes a link to recover from a failure and the network’s robustness in a catastrophe.
- Security:- Network security issues include protecting data from unauthorized access, protecting data from damage and development, and implementing policies and procedures for recovery from breaches and data losses.