Are you preparing for the Security+ exam? If so you need to understand some basic networking concepts.
As an example, see if you can answer this practice test question.
Q. Your organization has implemented a network design that allows internal computers to share one public IP address. Of the following choices, what did they MOST likely implement?
A. PAT
B. STP
C. DNAT
D. TLS
See if you're correct along with a full explanation here.