As with hydrostatics and the Statics portion of classical mechanics, the actual situation need not be 'static' and unchanging. Instead 'static' implies that the dynamic portion is being ignored, and we analyze frozen snapshots of the situation. In Electrostatics we study e-fields, voltage, and charge but ignore any currents and magnetism which may also be present. Because of its relationship and interaction with magnetism, the two fields are often combined as electromagnetism.

Coulomb's law

The fundamental equation of electrostatics is Coulomb's law, which describes the force between two point charges:

<math>F = \frac{\left|q_1 q_2\right|}{4 \pi \epsilon_0 r^2}<math>

Electric potential

Electric potential (also known as voltage) is another common and significant topic in electrostatics. Poisson's equation gives the relationship between charge distribution and potential:

<math>{\nabla}^2 V = - {\rho \over \epsilon_0}<math>