The Collection is the top level of organisation. There will be one collection per Karra instance.
Fields define data that can be collected for each object.
A Grouping Field is a hierarchical arrangement that can be used to group Objects. Objects can belong to multiple Groups. Examples: category, topic, etc...
These are fields that are used to record information about an Object. Examples: title, description, author, etc...
Objects make up a collection.
An Object can have one or more Files. Examples: multiple versions of the same image, a multi-page document as a series of images, etc...
The Metadata are the Field values that describe the Object.