I like Ruthi's answer in general. Let me add a few thoughts. Satisfaction is the more general term and is used in more situations. Gratification is more intense than satisfaction. You can both feel either yourself or do things that make others feel them. Both refer to emotional benefits, though they are used in phrases like, "physical gratification" to refer to the positive feelings from sexual activity.

A little difficult to explain -these words are similar. Satisfaction can mean being content with what you have done, or supplying a physical or intellectual need.For example you are satisfied after you have felt hungry and eaten a great meal,or after you have passed a difficult exam you will feel satisfaction with your performance. Gratification is similar as the dictionary definition says "he pleasurable emotional reaction of happiness in response to a fulfillment of a desire or goal" but I think the difference is more in the way we USE them.Gratification is often used more in the physical sense and less in the emotional one I think... maybe others will disagree.