[AHDEL](http://www.thefreedictionary.com/exhibit) gives the following definitions of exhibit:

>**exhibit** noun
>
>1. The act or an instance of exhibiting.
>
>2. Something exhibited: *studied the dinosaur exhibits at the museum*.
>
>3. A public showing; an exhibition: *spent the afternoon at the space exhibit*.
>
>4. Law Something, such as a document, formally introduced as evidence in court.

Judging from the third definition, *exhibit* and *exhibition* are synonyms, overlapping in OP's sense.