• Network set of devices(Nodes) connected by a communication links.
  • Computer network collection of autonomous computers interconnected by a single technology
  • Distributed system a collection of independent computers appears to its users as a single coherent system. e.g WWW

The effectiveness of a data communications system depends on four fundamental characteristics:

  • delivery,
  • accuracy,
  • timeliness,
  • and jitter.

Five components of data communication systems

  • Message
  • Sender
  • Receiver
  • Transmission medium — physical path by which message travels
  • Protocol — set of rules that govern data communication

Data flow