Hello Sameer
IGMP is a L3 protocol. It functions at L3 similarly to other network management protocols such as ICMP.
IGMP enabled routers will maintain a multicast group where a multicast address will be associated with the IP addresses of the hosts that have requested to be part of the multicast group. The show ip igmp groups command will show the IP addresses of the hosts that are associated with the specified multicast IP address.
On the other hand, IGMP snooping enabled switches will not maintain any such IP address associations (unless it is a L3 switch that performs IGMP functions of a multicast router). IGMP snooping is an exclusively L2 feature that cooperates with the functionality of multicast. It associates multicast MAC addresses with specific ports, those ports where hosts that are part of specific multicast groups reside.
More about IGMP Snooping can be found here.
Also, it is important to note that IGMP snooping must operate in conjunction with a multicast router. IGMP snooping on its own will not operate correctly. For more on this, take a look at this lesson:
I hope this has been helpful!
Laz