A floating IP is exactly the same as a public IP Address. As we use OpenStack for our Cloud, OpenStack names their public IP addresses floating IP's. Customers will do an ifconfig and see an internal IP. This is because we are using a NAT network. Routing to your floating IP ( public IP ) will work exactly the same as if the public IP was displayed in ifconfig.
A Floating IP as Defined in OpenStack which is what we use for our Cloud Machines:-
Each instance has a private, fixed IP address and can also have a public, or floating IP address. ... A pool of floating IP addresses, configured by the cloud administrator, is available in OpenStack Compute. The project quota defines the maximum number of floating IP addresses that you can allocate to the project.