What is the use of the 'netstat' command?

The 'netstat' command is primarily used to display various network-related information. It provides details about current network connections, including active TCP and UDP connections, and can show routing tables and interface statistics. This information is crucial for network diagnostics, troubleshooting issues like network congestion or connectivity problems, and understanding how data is flowing through the network.

This command helps system administrators and users monitor the network activity on their computers, allowing them to identify open ports, established connections, and the state of each connection. Such insights can be particularly useful in security assessments to check for unauthorized connections or services running that might be exploitable.

While the other options may touch on related concepts, they do not accurately describe the primary purpose of the 'netstat' command. For instance, displaying network speeds is more about bandwidth monitoring, managing user accounts pertains to system administration functions distinct from network monitoring, and optimizing network performance involves a broader range of actions, none of which are specifically addressed by the 'netstat' command alone.