Correct!The Class D address range, from 224.0.0.0 through 239.255.255.255, is reserved on the Internet for multicast. Multicast is the ability to define an arbitrary group of IP nodes and address messages just to that collective rather than broadcast to all nodes on the network or send point-to-point to each node individually.
The Class E address range, from 240.0.0.0 through 255.255.255.255 is reserved on the Internet and not to be used for any purpose.

