Electric dipole

If two equal and opposite charges +q and -q are separated by a distance 2d, then this arrangement is called electric dipole.

Gauss’s law

Electric flux ( φ ) through a closed surface (S) enclosing the total charge (q) is given by,

$$\phi = \frac{q}{\epsilon_0}$$

That is is the Gauss’s law.

Coulomb’s law

The force on a test charge Q due to a single point charge q is given by coulomb’s law $$\vec{F} = \frac{1}{4\pi \epsilon_0 } \frac{Qq}{r^2} \hat{r}$$ Where r is the distance between Q and q and ε0 is the permitivity of the free space.

What is an electric charge?

Charge is the properties of matter. According to Benjamin franklin there are two types of charge, (1) Positive charge and (2) Negative charge.
Electric charge is a scalar quantity.
In SI System, the unit of Electric charge is Coulomb.
The dimensional formula of Electric charge is [ M0L0T1A1 ]