Let's take an example of different processors(along with

their independent caches) sharing the same memory system.

Now if this memory is a Read-Write memory and let's say

that one of the processors writes to this memory after some

data computation, all the processors need to update their

individual cache copies of the now modified memory. To do

this the concept of snooping is implemented. cache snooping

is the means by which each cache constantly

monitors/detects the bus for any write to a memory location

and if a write is found, it invalidates it current copy of

cached memory data and copies the new content over.