Is there a difference between sunatta and anatta? if so, which is the difference?
I think sunyata is the
void that you experience when you see through the impermanence in things (
anitta). The reality is always vibrating. When you sit in vipassana and start observing, you will find that all your sensations are made up of these vibrations that constantly pulsate - they appear from nowhere and vanish instantly (anitta). Now, the emptiness or background in which the reality is vibrating is nothing but
Even modern physics has proved that matter vibrates at the quantum level, but you as a vipassana practitioner can actually observe the phenomena first hand! You don't have to take their word for it.
Anatta on the other hand refers to the realization that I am not this conditioned self. Continuing on the vibration concept above, if you keep pressing with vipassana, you will ultimately learn (with lots and lots of practice) that all perceptions, thoughts, mental formations and even consciousness are ultimately reduced to these vibrations. After vibes corresponding to physical sensations, follow the mental formations, perception, consciousness and so on. The result is that an illusion called
self is created by the vibe corresponding to consciousness impacted by the vibe corresponding to perception.
I've seen many interpretations, so I'll just give you the one I find most tenable/helpful.
Sunyata is the denial of any independent essence of a thing. Therefore, anatta is a type of sunyata, in which that independent essence is me.
Another way of looking at sunyata (a consequence) is that everything is interdependent (hence the lack of independence). This focuses on the independence aspect of the self that's denied.