How magnets work

The magnet consists of concentric clockwise and counterclockwise dipole rings that extend from one pole to the other over the entire body of the magnet.
Dipole rings in the same direction attract each other, and dipole rings in opposite directions repel each other. Likewise, currents in the same direction attract each other and currents in opposite directions repel each other.

An electric current can induce dipoles in a magnetic material to form dipole rings. Moving magnets can induce electrons in a conductor to produce an electric current. 

Since a dipole ring has two magnetic poles, clockwise and counterclockwise, there cannot be a single magnetic pole.