"Charge" is a general concept, and "charge carriers" (e.g., electrons) are specific examples of objects that have a net charge.
Both electrostatic force and gravitational force depend on 1/r122, the famous inverse-square law.
However, gravitational mass is positive-definite (no such thing as gravitational repulsion), while electrostatic charge has two polarities.
Before Franklin, in 1733 Charles Francois de Cisternay du Fay showed that charge had two types: "vitreous" (the result of rubbing glass with fur) and "resinous" (substituting amber for glass), and that like charges repelled each other and unlike charges attracted each other. Later, vitreous was defined as positive and resinous as negative, to go into Coulomb's Law for force.
In those pre-atomic days, the two types of charge were treated as fluids.
Newton (gravitation): F12 = Gm1m2/r122 and Coulomb (electrostatic) F12 = Kq1q2/r122
In Newton's law, the numerator is the product of two positive values and therefore positive definite.
In Coulomb's Law, the numerator can be positive (++ or --) for repulsive, or negative (+- or -+) for attractive.
(The formal vector equations for the two laws give the correct direction for the resulting forces.)
Of course, any lump of normal matter you encounter is neutral (or damned close) in charge, with equal positive and negative charges.
The charged balls used in Coulomb's torsion balance (capable of measuring small forces) had net charges far less than the individual totals of electrons (negative) and protons (positive) contained in the balls.
Since matter consists of huge equal amounts of protons and electrons, it is a matter of convention as to which is positive or negative.
Most elementary textbooks have an illustration of a current loop where different types of current are connected in series: for example, a vacuum diode, a copper wire, an ionic liquid solution, and the charge belt in a Van de Graaff accelerator.
The important charge carriers differ in each branch of the circuit, but the current flows in the same path around the loop.