In a digital circuits, the time taken for for the analog signal to switch digital state from a one to zero or the zero to one i.e. for the voltage to ramp from the “0″ voltage to “1″ voltage and vice versa.

For a engineers working at resellers, describes the communication with a customer where you are getting a purchasing commitment (zero to one) or the customer is losing confidence in you and looking elsewhere (one to zero). The steeper the slope, the faster the customer is coming to you or away from you.