Folders and files packaged together in one main directory on the server that work together to build an Omeka website. This is what your librarian will be working with if you choose Omeka.org and need to make any major changes to your site (an update for example).
The basic unit of an Omeka site. An item can be anything: a photograph, a work of art, an oral history, a short film, a section of a book, etc. You’ll describe each item and upload the relevant file or files. You’ll build your Omeka site by assembling items.
A set of items that you’ve grouped together. Your Omeka site can have multiple collections, but an individual item can only belong to one collection at a time.
A thematic tour of curated items. Each exhibit has pages, and pages can be nested. A page is a group of items with descriptions or supporting text. You can have multiple exhibits, and items can belong to multiple exhibits.
An item can be many different things. An “item type” is just the kind of thing the item is. You can choose from a built-in list of item types, or you can create your own. This tells Omeka how to handle the item.
A page on your Omeka site that isn’t part of an exhibit, item, or collection. For example, you can add an “About” page using Simple Pages. Pages can be nested.
A particular piece of code that enables a new kind of functionality. If you want your Omeka site to have a new feature (either on the administrative back end or the user-facing front end, you will likely need to install a plug-in. For a full list of available plug-ins, see http://omeka.org/add-ons/plugins/
Dublin Core Metadata
Metadata is a structured way of describing a digital object or group of objects. Metadata enables searching and is important for the preservation of digital objects. It’s important to be as thorough as possible when describing your content in Omeka. Dublin Core is a specific set of rules for describing content and it has a fixed set of “elements.” Elements are the different fields: Title, Creator, Subject, Description, Publisher, Contributor, Date, Type, Format, Identifier, Source, Language, Relation, Coverage, and Rights.
Tags are not the same as metadata. Metadata will stay with your objects if they are moved out of Omeka. Tags are unique to Omeka and will not stay with your content. They are used to help users browse Omeka and to allow you, the creator of the site, to map your own organization onto your content without violating the structure of Dublin Core. Use natural language and separate tags with commas.
A controlled vocabulary is an established list of standardized terminology for use in indexing and the retrieval of information. Controlled vocabularies become particularly important if you ever want to move your content to a new platform (out of Omeka). Some examples of controlled vocabularies you may want to use for the different fields are:
Library of Congress Subject Headings http://id.loc.gov/authorities/subjects.html
Getty Thesauri https://www.getty.edu/research/tools/vocabularies/
ISO Date Formatting http://www.iso.org/iso/home/standards/iso8601.htm
ISO Language Codes https://www.loc.gov/standards/iso639-2/php/code_list.php
DCMI Type Vocabulary http://dublincore.org/documents/2000/07/11/dcmi-type-vocabulary/
There are two types of coverage, temporal and geographic. For geographic coverage, use the Getty Thesaurus of Geographic Names. http://www.getty.edu/research/tools/vocabularies/tgn/