Which command provides a summary of disk space usage on all filesystems?

The command that provides a summary of disk space usage on all filesystems is "df -h." The "df" command stands for "disk free" and is used to report the amount of disk space used and available on filesystems. When the "-h" option is added, it formats the output in a human-readable form, displaying sizes in kilobytes (K), megabytes (M), or gigabytes (G) as appropriate.

This command is particularly useful for system administrators who need to quickly assess how much space is utilized and how much is available across all mounted filesystems. It summarizes total space, used space, available space, and the mount points for each filesystem.

In contrast, the other commands serve different functions:

• "du -h" displays the disk usage of a specific directory and its contents, rather than providing an overview of all filesystems.

• "ls -lh" lists files and directories in the current directory along with their sizes, but it does not provide information on filesystem usage.

• "stat" provides detailed information about a specific file or filesystem object, rather than a summary of usage across all filesystems.

This distinction makes "df -h" the appropriate choice for summarizing disk space