Coulomb (Unit)
Definition
The unit of electric charge — about 6.24 × 10¹⁸ electrons make one coulomb.
Symbol: · Unit: coulomb (C)
Technical definition
1 C = 1 A·s. The coulomb is defined through the elementary charge e = 1.602176634×10⁻¹⁹ C (exact by SI definition).
Example
A lightning bolt transfers roughly 15–30 coulombs of charge in a fraction of a second — a current near 30,000 A.
Common confusion
The coulomb measures charge, not current. Current (amperes) is coulombs per second — confusing them is like confusing liters with liters per minute.