Application forms can contain both "data fields" and "user fields".
Data fields affect the person and his attributes in VSys: name, address, certifications, etc. For example, placing the person's address on the application will update the address on all screens throughout VSys. These fields connect to where the data is stored in VSys One.
User fields do not use or affect data outside of the application itself, with the exception of the special field types of Availability checkboxes and Job slot selection. User fields can be added to store data that you don't otherwise have in VSys. Data stored in user fields is local to the application and is not editable, searchable, or reportable elsewhere.
User fields - those fields on the application which don't correspond to a "real" field in VSys itself - are shown in green in the application designer. Special fields like Availability, Trainings, and others are shown in orange here since all you'll see in the designer is a placeholder rather than the real editor. In both cases, the fields will show normally when they're used elsewhere.