current drive is any method of sustaining 📝plasma current without relying on the 📝central solenoid's induction.
A 📝Tokamak cannot confine a 📝plasma without a large current flowing through it, and by default that current is induced by transformer action: the central solenoid ramps its field, and the plasma acts as the secondary winding. The limitation is built into the physics — a transformer drives current only while its flux is changing, and the solenoid's swing is finite, so purely inductive operation is inherently pulsed. Current drive names the family of techniques that escape this limit: injecting beams of fast particles that drag current with them, launching radio-frequency waves that push electrons preferentially in one direction, and shaping the plasma so that its own pressure gradients generate 📝bootstrap current spontaneously.
The term is often used interchangeably with non-inductive current drive, its strict sense; the broader phrase "heating and current drive" covers the auxiliary systems that do both jobs at once, since the same beams and waves that heat a plasma can be aimed to drive current. Current-drive efficiency — amperes sustained per watt of power spent — is a central figure of merit, because a power plant that spends too much recirculating power sustaining its own current undermines its net output. Efficient current drive is the route to steady-state operation, the operating goal of practical 📝fusion power plants.