Could anyone explain briefly what exactly the sliding-mode for
nonlinear control is?

I tried several times finding from google but found nothing except
some applications of it.
I found one at wikipedia:
http://en.wikipedia.org/wiki/Sliding_mode_control

But I can't understand because I haven't taken any cource in Nonlinear Control Systems so it is a bit difficult for me to digest all these nonlinear topics (but I took Linear, Process & Digital Control a long time ago).

Thank you in advance :)

I tried several times finding from google but found nothing except

But I can't understand because I haven't taken any cource in Nonlinear Control Systems so it is a bit difficult for me to digest all these nonlinear topics (but I took Linear, Process & Digital Control a long time ago).

Thank you in advance :)