What is address sharing?with example?

Address sharing means to give 
a 
unique 
IPv4
 public 
address
 to 
each
 user.

for example  home LAN. or Office LAN.

This is done to provide an inherent security benefit.

That’s because host PCs on the Internet can only see the public IP address of the external interface on the computer that provides address translation and not the private IP addresses on the internal network.