"Archivist" versus "Conservator"
Often either title describes a very similar job that depends on the situation as well as organization that holds the collection.
A conservator focuses on preserving the state of an object to when it entered collection. This is done with research, documentation, and treatments that can be reversed in the future. The preservation of a collection is a shared goal of an archivists or conservator. But the archivist will likely be dealing with elements that were used to create a media object, not just a fixed final state of an object.
An archivist strives for the preservation of media objects, original order, and advocates for maintaining aspects of media, such as technical limitations inherent from the time of its making, as being key to the integrity of the original. In cases where the media itself is subject to update or alteration, such as when I'm working within an artist studio or post-production facility, I view the role as being an archivist rather than a conservator, as the state of an artwork may still be in a state of flux.