The common expression of Coulomb's law is that the interaction force between two static point charges in vacuum is directly proportional to the product of their charges and inversely proportional to the square of their distance. The direction of the interaction force is on their connection line, charges with the same name repel each other, and charges with different names attract each other.

This law was put forward by the French physicist Coulomb in his paper The Law of Electricity 1785. Coulomb's law is the first quantitative law in the history of electricity development, and it is also one of the basic laws of electromagnetism and electromagnetic field theory.

Gauss's law shows the relationship between the charge distribution in a closed surface and the generated electric field.

The electric flux through any closed surface (called Gaussian surface) S in electrostatic field is equal to the algebra of all charges in the closed surface, regardless of the charges outside the surface.