An electric current is measured in what?

Current is the rate at which electrons flow past a point in a complete electrical circuit. At its most basic, current = flow. Amperes, or amps, are the international unit used for measuring current. An amp expresses the number of electrons (sometimes called "electrical charge") flowing past a point in a circuit over a given time. A current of 1 ampere means that 1 coulomb of electrons—that's 6.24 x 1018 electrons—is moving past a single point in a circuit in 1 second.

Source: Fluke