What command provides information about block devices such as hard drives?

The command that provides information about block devices, including hard drives, is lsblk. This command lists all block devices in a tree-like format, showing the relationship between the devices and their partitions in a concise manner. It includes details such as the device names, sizes, types, and mount points, which are essential for understanding the storage structure of a Linux system.

This command is particularly useful for system administration tasks where you need to manage disks and partitions, check available storage, or troubleshoot issues related to disk space. The output helps users quickly identify the devices present in the system and their status, making it an invaluable tool in the context of block device management.