Hydrodynamics is the study of fluid motion. Historically "hydrodynamics" referred to the theory behind how water flows (and not the experimental study of water flow which was referred to as "hydraulics") and was first used by Daniel Bernoulli (1700-1783). The term is also commonly interchanged with "fluid dynamics." Hydrodynamics is relevant in soft matter studies, particularly in capillarity and wetting. For example, hydrodynamics is needed to fully describe dripping, jetting, or wetting phenomena.
For more information and interesting examples, check out:
- Stone, Howard. Lecture Notes for the Harvard University course Engineering Sciences 220: "Fluid Dynamics", Fall 2008.