A computer network or data network is a telecommunications network which
allows computer to exchange data. in computer networks, networked computing devices pass
data to each along network links [data connections].data is transferred in the form of
packets .the connections between nodes are established using either cable media or wireless
media. the best –known computer network is the internet.
network computer devices that originate, route and terminate the data are called network
nodes .nodes can include hosts such as personal computers, phones, servers as well
as networking hardware. two such device, whether or not they have a direct
connection to each other.
Computer networks differ in the transmission media used to carry their signals,
the communications protocols to organize network traffic, the network’s size, topology and
organizational intent. in most cases, communications protocols are layered on [i.e.work using]
other more specific or more general communications protocols, except for the physical layer that
directly deals with the transmission media.