What is the hydrosphere and why is it important?

NASA Worldview is a free online visualization tool that is a great launchpad for learners who are new (or veteran) users of satellite data.

Earth is made up of five major parts or subsystems: the Atmosphere, Hydrosphere, Biosphere, Cryosphere, and Geosphere. Each major part is connected to the other parts in a complex web of processes.

The Geosphere is associated with solid portions of the Earth. It includes the continental and oceanic crust and all other layers of the Earth's interior.  This includes all rocks, sediments and soils, surface landforms and the processes that shape the Earth's surface.