Pack ice refers to a large area of sea ice that forms from the freezing of ocean water. It consists of floating ice pieces that can vary in size and thickness, typically found in polar regions like the Arctic and Antarctic. Pack ice can shift and move with ocean currents and winds, creating dynamic and changing landscapes. This type of ice plays a crucial role in the Earth's climate system by reflecting sunlight and regulating temperatures. It also serves as a habitat for various marine animals, including seals, polar bears, and penguins, which rely on the ice for breeding and hunting.