The document discusses the Earth's freshwater hydrosphere and freshwater resources. It describes how only 3% of the Earth's water is freshwater, with most as ice (76%) or underground (23%). Less than 1% is available as surface water. It also outlines the water cycle powered by the sun and discusses different types of surface water like rivers, icebergs, and glaciers as well as groundwater stored underground in aquifers. Wetlands are also described as important habitats. Freshwater resources are then discussed, including drinking water supply and protection, as well as pollution sources like point and nonpoint pollution.