“A computer network or data network is a telecommunications network which
allows computers to exchange data. In computer networks, networked computing
devices exchange data with each other using a data link. The connections between
nodes are established using either cable media or wireless media. The best-known
computer network is the Internet” (Wikipedia)
Network computer devices that actually originate, route and terminate the data
are called network nodes, which can include hosts such as personal computers,
phones, servers as well as networking hardware. Two such devices can be said to
be networked together when one device is able to exchange information with the
other device, whether or not they have a direct connection to each other.
Computer networks are different in the transmission medium used to carry their
signals, communications protocols to organize network traffic, the network’s
size, topology and organizational intent.
Computer networks support an enormous number of applications are services
such as access to the World Wide Web, digital video, digital audio, shared use of
application and storage servers, printers, and fax machines, and use of email and
instant messaging applications as well as many others. In most cases, application-
specific communications protocols are layered over other more general
communications protocols.
Network services are applications hosted by servers on a computer network, to
provide some functionality for members or users of the network, or to help the
network itself to operate. The World Wide Web, E-mail, printing and network file
sharing are examples of well-known network services. Network services such as
DNS give names for IP and MAC addresses. Services are usually based on a service
protocol that defines the format and sequencing of messages between clients and
servers of that network service.
Depending on the installation requirements, network performance is usually
measured by the quality of service of a telecommunications product. The
parameters that affect this typically can include throughput, jitter, bit error
rate and latency.
There are many ways to measure the performance of a network, as each
network is different in nature and design. Performance can also be modelled
instead of measured. For example, state transition diagrams are often used to
model queuing performance in a circuit-switched network. The network planner
uses these diagrams to analyze how the network performs in each state,
ensuring that the network is optimally designed
Links:
https://en.wikipedia.org/wiki/Computer_network
https://en.wikipedia.org/wiki/Routing
https://en.wikipedia.org/wiki/Telecommunications_network
Questions:
What are advantages and disadvantages of wired and wireless technologies?
Why is it important to have a protocol?
What is the ethic problem of the use of computer network?