Link: A Link is a network that allows a set of computers to communicate with each other.

eg 1:
if all computers in an office are wired together, the connection makes a link

eg 2:
If several computers belonging to a private company are connected via a satellite channel, the connection is a link.

q).What is internet and intranet ?
ans).
*.These private networks are often referred as intranets.
*.The public internet(that is global network of networks) is the
  network that one typically refers to the internet.