a motor turn is how many times a strand of wire is wrapped around the armature webbing.
for example - an 10x1 (10 single) would be a single strand of copper wire wrapped around each armature webbing 10 times.
15x3 (15 triple) - 3 strands of wire are wrapped around each armature webbing 15 times
19x2 (19 double) - 2 strands of wire wrapped wround each armature webbing 19 times.
the less turns the faster the motor - i.e. 10 turn faster than a 19 turn, etc.