how to know if you have ssd or hdd code example

Example 1: check ssd or hdd linux

$ cat /sys/block/sda/queue/rotational

#If the output is 1, the disk is HDD.
#If the output is 0 (zero), the disk is SDD.
#Because, SSDs won't rotate. So the output should be zero
# if you have SSD in your system.

Example 2: how to tell if hard drive is ssd

Run 'dfrgui' on command prompt