Biophysics is the union of biology and physics. Physics is the study of the laws that the natural universe obeys, whereas biology is the study of life. Biophysics is an attempt to understand the laws that govern biological systems from the atoms and molecules within biological organisms to the environment.Biophysicists use the laws, techniques, and tools from physics and apply them to biological systems.

Biomechanics, which is the study of the interaction of biological organisms with their surroundings, is an important area of biophysics. A solid understanding of biomechanics is important for people interested in kinesiology, physiotherapy, occupational therapy, and bioengineering. Biomechanics also deals with the small objects, such as the interaction of cells with their surroundings.

Gasses and liquids are considered fluids. If you have ever watched smoke rise from a fire or a stick float down the river, you can see the way the fluid moves can be very complicated. The good news is that not all the types of motion of fluids are complex and complicated, but some types of motion can be modeled and well understood.

The ability of people to produce and hear sound is a very important part of everyday lives. Biophysics tells you what the properties of waves are, and it tells you that sound is a longitudinal pressure wave (in air) that is produced by mechanical vibrations. Biophysics also tells you how people can produce pressure waves for communicating with others and for singing.