Tasers - why don't they hurt in long range mode?

I read in wikipedia that tasers when used as a projectile don't primarily serve to cause pain but to control the muscles of the victim. On the other hand, using them in the drive-stun mode (no projectile, manual contact of the taser with the target) is intended to cause pain. What is the difference between the two that is responsible for the two different effects? Aren't they both just high voltage shocks?