DDR5 vs GDDR5

[Weak1ings]

I know some of you may say that DDR5 is nonexistent and, does not exist for motherboards yet but The reason this question has arrived is such:
The Zotac Amp! Extreme GTX 970 has 4 GB DDR5. Normal GTX 970s have GDDR5 and I'd like to know what the difference is.
Amazon, PCPartipicker, Newegg, and many other sites all say DDR5. So yes, it does exist and is also apparent on the non Extreme card.
http://pcpartpicker.com/part/zotac-video-card-zt9010310p

So what is the difference?
If I had to buy a GTX 970 This card would be my choice.

 

[TopLuca]

Its GDDR5 on the Zotac 970 , they both refer to the same thing .

Most people when they write DDR5 or GDDR5 they are referring to GDDR5 , that's based on DDR3 If I am not wrong.

DDR5 is yet to be released as DDR4 is still very new.