Coulomb's law states that the magnitude of the electrostatic force between two point charges is directly proportional to the product of their magnitudes and inversely proportional to the square of the distance between them.
Point charges are objects that have an electric charge concentrated at a single point. They are used in calculations involving electrostatic forces because they simplify the analysis by assuming all charge is concentrated at a single point.
Electric Field: An electric field is a region around a charged object where another charged object experiences an electric force. It can be thought of as invisible lines extending from positive charges and terminating on negative charges.