It becomes clear that it does not have an exclusive object of study, nor does it have an exclusive body of knowledge. The difference is largely one of focus. Geography, including physical geography, has always been a generalized discipline, rather than a specialized discipline, such as the ones listed above. Things here, of course, mean natural phenomena. Specialized branches of Earth science provide us with valuable knowledge about the internal works of Earth systems.
Physical geography provides an effective environment for such integration.
The concept of landscape serves as the central point for synthesis in physical geography. The global Earth system is enormously complex. One useful approach is to look at the physical state of Earth materials. You can think of the Earth as being made of concentric spheres of matter in different physical states. Hydrosphere - water on Earth, including oceans, lakes and rivers, glaciers, etc.