Difference (noun):
1. A point or way in which people or things are dissimilar.
Example: "There are some differences between men and women"
Differential (adjective):
1. Constituting a specific difference;
2. showing/depending on a difference
Example: "At present, it is unclear why there is a differential requirement for such factors."
Different (adjective):
1. Not the same as another or each other
Example: "You can play this game in different ways."