Right. Stick your right arm out with your thumb pointing towards yourself and your hand partially opened. When you rotate whatever fastener you happen to be working with the way your fingers are pointed, it will advance in the direction your thumb is pointed. If you turn your hand around, you will be rotating the opposite way, but the fastener will also be advancing the opposite way. That's what makes a "Right Hand" thread.

A "Left Hand" thread works the same way, except with your left hand. That's the whole purpose behind throwing the word "Hand" into the description of the thread type.

If you know whether the fastener in question utilizes right hand or left hand threads, all you have to do is use that hand and point its thumb in the direction you want the fastener to advance along the threads, and your fingers on that hand will point you out the way to turn the fastener.



Edit: It's like the "Right Hand Rule" for angular momentum, for anybody who has studied college physics.