User blog:Piisfun/The difference between a prank and a troll.

While these two terms are often used interchangeably, they have very different meanings.

Pranks

 * nondestructive
 * funny even to the target

Trolls

 * laughter at the expense of others
 * if personal, it is a form of bullying
 * if in the public domain, it destroys the contributions of others, or compromises public resources, making them unusable.