How do you monitor system resources in real-time?

Monitoring system resources in real-time requires tools that can actively display the current usage of CPU, memory, processes, and other vital system metrics. Tools such as 'top' or 'htop' are specifically designed for this purpose.

The 'top' command provides a dynamic, real-time view of system processes, displaying the usage of CPU and memory by each process as well as other critical performance data. 'htop' is an enhanced version of 'top' that offers a more user-friendly interface with interactive features such as the ability to easily kill processes or sort the output.

The other options include tools that serve different functions and do not provide real-time resource monitoring. For instance, 'shutdown' and 'reboot' are commands used to alter system states rather than monitor performance. Similarly, 'vi' and 'nano' are text editors used for editing files, and 'ls' and 'cd' are commands for listing directory contents and changing directories, respectively. None of these tools are related to real-time monitoring of system resources. Therefore, using 'top' or 'htop' is the appropriate and correct choice for monitoring system resources in real-time.