A digital object is essentially a set of bit sequences that are the digital representation of a thing. Examples of digital objects include the scanned jpgs or tifs of a physical letter, the mp3 file of a recorded audio interview, the mov file of a digitized film, a database or data set, the 3-D rendering of a model, and more!
An item in Omeka is a digital object or a set of related digital objects that represent a whole. An item could be the pages of a letter, an oral history and a text transcript, a data set, or multiple photographs of a single person. If you have multiple digital objects, you may chose to treat them as a single item or you may treat each digital object as its own item and connect them to each other in Omeka via a collection or an exhibit.
A collection is a way to bring together similar materials in Omeka in a visual way. It can be made up of one or more items that you want to keep together. For example, a collection could be a set of newsletters of the same title, a group of items created by the same person, data from a sequence of experiments, or a series of historic maps of the same location. You do not need to create a collection or collections before adding items. You can also move items into a collection later or move them to a different collection if you decide to reorganize your items.
An exhibit in Omeka is an intentionally (curated) bringing together of related items. Whereas a collection simply brings items together in a list with thumbnails, an exhibit is a way to display items in a specific order, to create individual pages, and to incorporate plugins and other external tools for a more interactive experience. This is Omeka's primary purpose and items and collections are the support structure.
Are you working on an Omeka project? Do you need help getting started? Stuck on an issue or have a problem you can't resolve? Email us (email@example.com) and we will connect you with someone at the University Libraries who will try to help!