Is wordnet an example of a treebank? If not, what are the differences? I'm not sure but may be a treebank contains parse trees but wordnet does not. Thanks.
Treebanks are about sentences analysed with syntax trees (constituent and/or dependency parsing).
Wordnets are about semantic relation between words like hypernymy and hyponymy.
The two resource types have different objects as their contents and they are analysing different kinds of relations between those objects. Besides being linguistic resources for specific languages, they have almost nothing in common.