What does NAT (Network Address Translation) primarily accomplish in a network?

Network Address Translation (NAT) primarily serves to hide internal IP addresses. This functionality is crucial in a networking context, as it allows devices on a private network to communicate over the internet while concealing their actual private IP addresses from external entities. Instead of exposing internal IP addresses, NAT translates them into a public IP address that is shared among multiple devices.

This not only protects the internal network but also helps in conserving the limited supply of public IP addresses available. By translating multiple private IP addresses to a single public IP address (or a few public IP addresses), NAT enables better security and privacy by preventing direct access to internal network devices from outside the network.

In contrast, the other mentioned options do not capture the primary role of NAT. Increasing bandwidth, securing physical connections, and improving network speed are functions that NAT does not directly address; rather, NAT focuses on the management and translation of IP addresses for both security and efficient use of IP address space.