What’s a forest and what’s a jungle?

I was just telling kun about Hasan going to the forest the other day when I started asking myself, what is it that Singapore have, really - forest or jungle? And then I started to ponder over the difference between the two...stupid, I know. But unfortunately I truly cannot tell the difference between a forest and a jungle, much less define them.

Picture above though has got nothing to do with forests or jungles in Singapore at all. Picture shows an after effect of a slash and burn of a forest (I think) in Geeveston, Tasmania. I found the picture after looking thru forests pictures I have taken during field trips with uni subsequent to the forest-jungle confusion. And I thought this pic looks kind of good for the post. So I decided to put it up here, that's all.