Ice floes are frozen masses of seawater (saltwater) that float on the surface of the sea. The term is applied to any relatively flat piece of sea ice that is free moving.
When sea water freezes, the salt is left behind (this is called brine rejection), so ice floes and icebergs are generally composed of fresh water. There have been various schemes to tow icebergs to...
Ice flows consists of surface ice. Ice bergs are a huge piece of thick ice, the majority of which is under water. It's been said that as much as 80% of an ice berg is under water.
Polar bears, though excellent swimmers in ice-cold waters, are land animals. If one is far offshore and a floe is nearby, maybe it will clamber up onto the floe to have a nap.