ELECTROSTATICS:
The branch of physics in which we study the properties associated ( correlated) with the charges at rest.

ELECTRIC FORCE:

The force of attraction or repulsion between two charges is called electric force.

KINDS OF CHARGES:

There are two kinds of charges.
(i) Positive charges
(ii). Negative charges
For example, the charge on a proton is positive and its value is +1.6×10-19C. The charge on an electron is negative and its value is —1.6×10-19C. The charge of an electron is equal to the magnitude of that of a proton, but opposite in sign.

PROPERTIES OF CHARGES:

(i) Like (Similar) charges repel each other.

The figure shows a repulsive force between the like charges.
(ii) Unlike (dissimilar) charges attract each other.

The figure shows an attractive force between the like charges.