Public or Private?

Many organizations successfully reduce their risk to external connection
by designating specific resources as either public or private. Private
resources are NOT accessible through any external connection, and if all
else fails with respect to security, those protected resources will ensure
that you do not go out of business from being hacked.
Public types of resources can be protected by using an applicationlayer
security protocol. For example, transport layer security (TLS) is a
flavor of the more commonly used secure sockets layer (SSL) that you
use whenever performing a purchase transaction over the Internet so
that your credit card information is not intercepted while in transit from
your workstation to the server.
Private resources are protected either by permitting only local wired
connections to access them, or by creating the next best thing—VPNs
that make certain that even if those resources are intercepted they are
unusable to the hacker because they are encrypted in a strong and
secure manner. VPNs are one means of making certain that wireless
hackers are unable to eavesdrop or access unauthorized private
resources anywhere on your network.