(
Hard 
Disk 
Drive/
Solid 
State 
Drive)  A designation for the two types of storage drives in common use.  The HDD/SSD label (or SSD/HDD) in a user manual refers to the main drive in a desktop or laptop computer, which can be either type.  The storage in a smartphone or tablet is always an SSD.  See 
hard drive, 
SSD and 
hybrid drive.