Hi,
"Four quadrants" refer to a diagram with two axis...and each of the axis may have positive as well as negative values.
Quadrant 1: X = pos, Y = pos
Q2: X =neg, Y = pos
Q3: Y = neg, Y = neg
Q4: X = pos, Y = neg
Now it depends what your both axis are. This is not clear in your question.
For the contol circuit of a DC motor the axis could be: X = voltage and Y = current.
Then the four operation modes can be:
Q1: normal motor operation in forward direction, CW rotation.
Q2: rotation forward, but current = negative = motor operating as generator
Q3: normal motor operation in reverse direction, CCW rotation.
Q4: rotation reverse, but current = positive = motor operating as generator
Klaus