What are fields?

All entries in a content type need to have certain information associated with them.  By default, WordPress lets you add things like titles, content, and authors. For your custom content types, you will inevitably need more specific information.  For example, a "Movie" content type might need fields for Synopsis, Release Date, Running Time, Poster, Rating, and Official Site. A field is just a single piece of information.  It can be a simple text field, a large text box, a date, a file, a checkbox, and more. Taxonomies (a list of specific options, displayed in a dropdown, checklist, or radio button list) and Connections (direct relationships between multiple entries) can also be added as fields.

"Field Groups"

SmartSimian enables you to create Field Groups, or sets of these fields.  These field groups can then be added to one or more content types.  Each field group can have as many fields as you like. Field groups are controlled via the “Fields” item in the Creator menu of the dashboard.  Through there, you can reach screens that enable you to view all field groups, edit the fields within an existing field group, or add a new field group.