What is the difference between 'charge' and electron/proton?

What is the difference between 'charge' and electron/proton?

The unit of charge (called Coulombs, after the physicist who coined it) was developed before people knew about electrons and protons. When they discovered the source of the charge, they measured how much of the already established unit of charge was carried by a single electron.

Since for most purposes, there are lots and lots of electrons involved, it's easier to use the older system. However, there is another system where the charge of an electron is 1e (e being the unit of electron charge).

Different units are used for different purposes. The natural units system relies on setting fundamental constants to 1 unit and bases everything else off that. e is the charge of an electron. c is the speed of light, and h is plank's constant. In quantum mechanics, where they deal with individual atoms, these units are often used instead of meters, seconds, coulombs, kilograms, etc.

Charge
- there are two kinds of charge, positive and negative
- like charges repel, unlike charges attract
- positive charge comes from having more protons than electrons; - - negative charge comes from having more electrons than protons
- charge is quantized, meaning that charge comes in integer multiples of the elementary charge e
- charge is conserved