What information does the 'who' command provide in a Linux system?

The 'who' command in a Linux system is designed to display information about the users currently logged into the system. It shows each user's login name, terminal, the time they logged in, and sometimes other details like their originating IP address or hostname. This is particularly useful for system administrators and users who need to monitor active sessions on a multi-user system, allowing them to see who is currently accessing the machine.

The other choices address different aspects of system information. The first choice relates to firewall rules, which can be managed typically with commands like 'iptables' or 'firewall-cmd'. The third option refers to network configuration details, which can be viewed using commands such as 'ifconfig' or 'ip addr'. Lastly, disk partition details can be obtained using commands like 'df' or 'lsblk', which provide information about mounted filesystems and disk space usage. All these commands serve distinct purposes and do not overlap with the functionality of the 'who' command.