a floating ip range is provided to the external network that is used to provide floating IP's to tenant VM's on demand/request. you can get a detailed listing of your network Allocation pool using the below command.

openstack subnet list --long

A "pool" is just the address range configured on an external network. Get information on that network, and you have information on the pool.

Hi, there is no more strictly speaking 'pool' in Neutron networking controlling floating IPs (that was the case of Nova) 'neutron floatingip-list' is Neutron CLI command for that