Define NAT (Network Address Translation) and explain its significance in modern networking.

Network Address Translation (NAT) is a method used in networking where IP addresses are translated from one group to another, often for the purpose of preventing the need for every device to have a unique IP address. This is particularly useful in situations where IP addresses are limited, such as in IPv4.

Here's a step-by-step explanation of NAT:

1. Definition: NAT stands for Network Address Translation. It's a technique used in networking to save IP addresses.

2. Function: NAT translates the IP addresses of computers in a local network to a single IP address. This single IP address is used in all traffic routing, so it represents the entire group of computers to the outside world.

3. Significance: NAT is significant in modern networking for a few reasons. Firstly, it conserves the limited number of IP addresses available by allowing many devices to share a single IP address. This is particularly important in IPv4, which has a limited number of available addresses. Secondly, NAT adds a layer of security because the IP address of a specific device in the local network is never directly exposed to the internet. Instead, all incoming traffic goes through the translated address, which can then be routed to the appropriate device.