Positive and negative reinforcement are the same in that they each strengthen behavior by rewarding it. Positive reinforcement strengthens a behavior by adding a desired consequence in response to the behavior. An example of positive reinforcement would be when a child is rewarded for her good grades by being taken out to the movies. Negative reinforcement strengthens a behavior by taking away an undesired consequence when a certain behavior is exhibited. If a child's mom is always nagging her to wash the dishes and when she does do the dishes her mom stops nagging her, then negative reinforcement has occurred because an undesired stimulus (the nagging) has been removed. Positive reinforcement is more effective in shaping behavior because it adds a desired consequence and, as a result, creates a positive motivation to continue the behavior.
Both negative and positive reinforcement can be applied in operant conditioning, as both are processes by which behavior is shaped. A desired or sought behavior can be rewarded by adding something desired, or by taking away something undesired. Either way, the behavior is encouraged or strengthened. As applied to people, operant condition is psychologically more effective when a desired stimulus is supplied in response to a target behavior.
I have a few things to take care of first, but I can add some to this in a couple of hours. Is that soon enough.