The total charge of universe remains constant. It may alternatively be stated as follows : "The total charge of an Isolated system remains constant i.e. for a closed system of particles.'' or The algebraic sum of all the charges in an isolated system is a constant..

`sum_i e_i^+ - sum_i e_i^- =` Constant

The above principle suggests that :
(a) Charge can neither be created nor be destroyed.
(b) Two types of charges. One type is positive and other type is negative
(c) Only `(+)ve` or only `(-)ve` charge can never be created.
(d) Simultaneous production of equal and opposite charges or simultaneous annihilation of equal and opposite charge don't violate the principle of conservation of charge.