One of Omeka’s strengths is how it handles metadata – the data about the data that allows it to be searched and found. Omeka has Dublin Core built in as the default metadata setting, although it is possible to also use other metadata systems on Omeka.
The Dublin Core Metadata Element Set is a vocabulary of fifteen properties for
use in resource description. The name “Dublin” is due to its origin at a 1995 invitational workshop in Dublin, Ohio; “core” because its elements are broad and generic, usable for describing a wide range of resources.
There is a certain amount of flexibility in how one interprets each element of Dublin Core – which is a strength but also a challenge for someone trying to learn how to use it! Figuring out what is an appropriate entry for the Subject element or Type or any of the other elements can be perplexing.
In many ways I have been learning by doing, reviewing and then, hopefully, doing better.