Final answer:
The lsblk command lists all block devices and partitions on a system. The number of disks and partitions will be shown by this command and varies per system, identifiable by names like 'sda' for disks and 'sda1' for partitions.
Step-by-step explanation:
The lsblk command, which stands for "list block devices", displays information about all available or the specified block devices. It reads the sysfs filesystem to gather information. When you run the lsblk command in a terminal, it will list all block devices, such as hard drives and partitions they contain, on your system.
To answer how many disks and partitions you have, you would need to count the number of devices listed that represent disks (usually with names like 'sda', 'sdb', etc.), as well as the number of partitions under each disk (indicated by a number appended to the disk name, like 'sda1', 'sda2', etc.). The number of disks and partitions can vary depending on the specific system.