Two wires, a stepper it ain't.
You need two axes (in three or more wires) to provide directional information. Otherwise it's just pulsing on and off, and some lucky timing, or contrivances, can make a net rotation, but not anything in the same general way that a multiphase motor does.
Could be "single phase" BLDC?
Or it's for angle, not rotation, and it's an oversized d'Arsonval movement, say?
On multiphase:
Single phase induction motors normally start up thanks to a "start" or "run" winding that is electrically phase shifted. The phase shift sets up a rotating component to the magnetic field, which drags the rotor along and makes it spin. The electrical means is usually an L/R or LC time constant: hence the shorting bar in "shaded-pole" motors (L/R), or the "run" capacitor in split phase motors, some induction motors, and rotary phase converters. These are frequency-dependent elements, so they only work over a modest frequency range, and the starting torque drops very quickly as frequency falls. Whereas a multiphase induction motor can run down to DC with maximum torque proportional to frequency (using a VFD to drive it), and a synchronous (permanent magnet) motor can run down to DC period -- a true "four steps per revolution" stepper, as such.
You can't have less than 4 steps, because the two phases are driven in quadrature, and each step is 90 degrees, both electrically and mechanically. You can always have more steps, by dividing the magnet and coil into more poles.