Timing:
During classical conditioning the timing has to be very close so the organism can associate the UCS and CS.
During operant conditioning, initially you will have to provide the reinforcement/punishment after the desired response has been made with little time gap so the organism can associate the consequences of the behavior. However, you will need to use partial reinforcement to strengthen the learned response even more, for example by not reinforcing every correct response the organism is more likely to do the desired response because they expect that they will be reinforced if they do the correct response.
Type of response
The type of response is usually involuntary requiring little conscious awareness (e.g. salvation in the case of Pavlov's dog - it was involuntary and was in the control of the ANS) for classical conditioning whilst it is usually voluntary in the case of operant conditioning as the organism can choose to respond in a particular way and therefore the CNS is more active, but in some cases it can be involuntary.