what is stack profile in zigbee

what is stack profile and profile_id. I have seen three types of stack like


Z-Stack™ Energy

Z-Stack™ Home

Z-Stack™ Lighting

why this is divided in to these categories?? any way zigbee will do same job for all know. I have seen in zigbee.org, i didn’t understand. can any one tell me in short words

Stack Profile is a name for a particular zigbee type implimentation. The examples you gave are likely very closely related. Think of them as cousins.

The reason we have different stacks in zigbee is because they can specialize in doing different tasks better than if we all were forced to use the same Stack Profile.