Electric charge is another physical property attributed to fundamental particles.
The description of electric charge as in Wikipedia is:
Electric charge is the physical property of matter that causes it to experience a force when close to other electrically charged matter. There are two types of electric charges – positive and negative. Positively charged substances are repelled from other positively charged substances, but attracted to negatively charged substances; negatively charged substances are repelled from negative and attracted to positive. An object will be negatively charged if it has an excess of electrons, and will otherwise be positively charged or uncharged. The SI derived unit of electric charge is the coulomb (C), although in electrical engineering it is also common to use the ampere-hour (Ah), and in chemistry it is common to use the elementary charge (e) as a unit. The symbol Q is often used to denote a charge. The study of how charged substances interact is classical electrodynamics, which is accurate insofar as quantum effects can be ignored.
The electric charge is a fundamental conserved property of some subatomic particles, which determines their electromagnetic interaction. Electrically charged matter is influenced by, and produces, electromagnetic fields. The interaction between a moving charge and an electromagnetic field is the source of the electromagnetic force, which is one of the four fundamental forces (See also: magnetic field).
The electric charge is manifest as a force close to other electrically charged particles. In the Standard Model, the electron has an electric charge, while assumed to be a point particle. How to describe and visualize the impact of an electric charge? It requires understanding a point particle as being non-tangible and non-visible without spatial extension, but with mass and an electric charge. This implies the electron to be material and physical.
This interaction is exerted in space and we assign to an electrically charged particle the property of an “electromagnetic field”. This electromagnetic field is also not a physical reality, but an interference potential when electrically charged particles are moving relative to each other on short distance.
The description tunes towards the impact of an electric charge on other particles under specific circumstances and conditions.
Electric charge is a relativistic invariant. That means that whatever amount of energy we deploy in, for instance, a hadron collider, it does not create an impact on the electric charge. The relativistic mass may increase enormously, but it does not affect the electric charge of the matter. Also, the electric charge is independent of the invariant mass, because the electric charge of an electron and the electric charge of a proton carry the same amount of charge, but with a perceived different character. We define this perceived difference into a positive and a negative electric charge.
A positive and a negative charge attract each other. That has been formatted in Coulomb’s law. By convention, the electric charge of an electron is negative and that of a proton positive. The absolute values of both types of charges are assumed to be equal, as they may annihilate each other.