This document discusses different types of meters used to measure electrical current, including direct current meters that use a moving coil in a permanent magnetic field to deflect a pointer. It focuses on D'Arsonval meters, which have a coil suspended by a taut band that allows the coil to rotate in response to current. The coil is attached to a pointer that indicates the measurement on a scale. The document also describes the components of D'Arsonval meters such as the ferromagnetic core, magnet, and yoke.