Meaning – The term group address, refers to a single transport address identifying a collection of users. The collection of users is formed so that they can all receive common multicast datagrams.
Group addresses are used in organizations where data is to be transferred or shared between multiple groups of employees. Therefore, each group is assigned a group address on the network, and the network administrator can control the data being shared or transferred between these groups.
Group addresses are kept private or public, depending on the context, and this is totally controlled by the network admin within the organization.