Sata Terminology meaning of snoop

[love_hate_and_repeat]

when i read sata controller chapter in t1042 reference manual, i encountered snoop word but i didnt understand the meaning of snoop word in sata terminology.

the specific part i didnt understand is that "Data snoop enable bit. When this bit is set, all data read/write operations associated with the PRD entry for this command will be snoopable".

can you explain it in easy way ? 

[love_hate_and_repeat]

Firstly, Thank @ufedor  for  your answer. some questions come to my mind after your answers.

* If I use DMA for sata read/write operation, is it necessary enabling snoop bit ? There is also snoop enable bit in DMA module for both read and

write operations. what is the difference between SATA snooping and DMA snooping in terms of CPU when I enable both of them.

* If  I use only single core, is there any advantage of enabling snoop for sata or any kind of device?

Thanks in advance.

[ufedor]

This means that read/write operations, associated with data area described by current PRD, will generate cache coherent transactions on the internal system bus.