lscpu
Reports info about the cpu and processing units.
lshw
Reports detailed/brief info about multiple hardware units like cpu, memory, disk, network adapters etc.
lspci
Lists out all the pci buses and details about the devices connected to them.
lsscsi
Lists out the scsi/sata devices (hard drives/optical drives).
Inxi
10K line mega bash script that generates a GOOD looking report based on hardware details from multiple sources and commands.
lsblk
Lists block devices.
df
Reports various partitions, mount points and the used/available space on each of them.
mount
Mount/unmount and view mounted file systems.
free
Checks the amount of used, free and total RAM.
hdparm
Reports info about sata devices (hard disks. etc)
Copied.
Reference:
http://www.efytimes.com/e1/fullnews.asp?edid=142802