close loop and open loop

Yesterday, I read an article. The system described seems to me as close loop system. But instead it is called open loop system. So I search google and wikipedia today. Now I am total confused.
http://www.atp.ruhr-uni-bochum.de/rt1/syscontrol/node4.html
As I understand, for the open loop the state used to adjust control is variable outside the system. That is, if the system is disturbed, the control won't response.

But in http://en.wikipedia.org/wiki/Open-loop_controller
It defines

An open-loop controller is a type of reactive
controller which computes its input into the system using only the current
state and its model of the system. It does not use feedback to determine if its
input has achieved the desired goal.

By this definition, current state can be affected by disturbance. That is, if the system is disturbed, the control may response later instead of immediately.

Which understanding is right?