A collector characteristic curve is a graph showing:

• emitter current (IE) versus collector-emitter voltage (VCE) with (VBB) base bias voltage held constant
• collector current (IC) versus collector-emitter voltage (VCE) with (VBB) base bias voltage held constant
• collector current (IC) versus collector-emitter voltage (VC) with (VBB) base bias voltage held constant
• collector current (IC) versus collector-emitter voltage (VCC) with (VBB) base bias voltage held constant