Unplugging Dvd Device While Machine Is On

Hi, i have just a very simple question.

Can i plug/unplug an internal DVD device while the machine is On??

Will it damage any of the harware or is there any danger??

Also, if not, is there a difference between unplugging the connection between the DVD and the mobo and unplugging the connection between the DVD and the feeder (i'm not sure this is the right word since my english is not very good ^^: i mean the power. )

Thanks in advance

Common sense is that you should never unplug any hardware component while a live voltage current is going through the system, especially while the computer is running. Just because your computer is powered down unless you've unplugged it from the outlet then it still has current, though minimal, as indicated by the motherboard power LED. Also ensuring you wear a static wrist strap while tinkering around inside your computer case will help to ensure static discharge doesn't cause damage to sensitive components.