Check out this article by a librarian from the Library of Congress on what curation means.... Here is an excerpt:
I came to understand that someone identified a context or message that one wanted to present, and brought together a set of objects that represented a place or time or context, or provided examples to illustrate a point. The exhibition wall texts and labels and catalog and web site are carefully crafted to contextualize the items so they do not appear to be a random selection.