What is the difference between PCID : 0 and PCID : 6 frame structure?

Hi Experts,

What is the difference between PCID : 0 and PCID : 6 frame structure

from the frame structure it seems same

1.If so what is the significance of having many PCID’s with same frame structure?
2.PCID is used only to derive CRS positions ? Or does it have any other significance