I ask because anymore it seems to be that anyone you complain to considers you a whiner. Before that, whining was used to refer to pouty children. So, how do you distinguish them from each other?
That being said, I do agree with the above answerer that whining is NEVER constructive whereas a complaint can be legitimate if presented appropriately.
I'm not saying the other answers aren't correct, but I think the difference is the tone.
Complaining may have a constructive purpose; whining serves no purpose other than to annoy. Sometimes people complain just to get "something out of their system." It's not really whining, but it doesn't do any good but to relieve the feelings of the complainer.