Hindsight is to do with things that happened in the past. For instance, if you did something in a particular way and then after that found a way to reduce the time in hindsight you could have saved time by performing the task in the more efficient maner. Its kind of expression used when you wish you did it differerntly. Bacially, its about learning from mistakes.

Foresight on the other hand deals with events that haven't happened yet. If for example you plan to build a fence foresight would be the ability to predict what you would need to do to get the task done.