Which command is used to display disk usage for the file system?

The command used to display disk usage for the file system is indeed the one that provides an overview of available and used space on file systems. This command, when executed, shows the total size of the filesystem, along with how much space is used and how much is available. It also typically lists all mounted filesystems, making it a valuable tool for understanding overall disk usage at a glance.

In contrast, while the other commands have their specific purposes, they do not provide a comprehensive overview of disk space usage for the filesystem as a whole. For example, one command focuses on the disk usage of individual files or directories, while another provides detailed information about files but not the overall filesystem statistics. Thus, the selected command stands out as the appropriate choice for displaying disk usage across the file systems mounted on a Linux system.