Question

what is a charge in physics ​

Answer 1

In physics, a charge may refer to one of many different quantities, such as the electric charge in electromagnetism or the color charge in quantum chromodynamics. Charges correspond to the time-invariant generators of a symmetry group, and specifically, to the generators that commute with the Hamiltonian.

Answer 2

charge is the physical property of matter that causes it to experience a force when placed in an electromagnetic field.