a computer network that covers a broad area across metropolitan,

regional, or national boundaries.

physical or virtual appliance that passes information between two or

more packet$-$switched computer networks

layer of the Internet Protocol Stack that routes frames from one node

to adjacent node over a link

a computer network that is concentrated in a geographical area, such as a

university or corporate campus.

a unique identifier that defines a specific subnetwork within a larger

network

an end$-$to$-$end layer that is used to deliver messages to a host, which

manages network traffic between hosts and end systems to ensure

complete data transfers.