Vacation Type in Vacation Manager are mapped to JIRA Issue Type and can be chosen by User when creating new Vacation Document (1), just like any other Issue Type (2).
Vacation Type globally holds properties and describes details of vacation, and can be added or removed from system only by Admin.
You can get more information about available types and properties of Vacation Types in Managing Vacation Types section.
Technical details
After creating new Vacation Type, Vacation Manager automatically creates new Issue Type with same name and connects it to VACMAN Issue Type Scheme used by Vacation Manager Project.
Next Vacation Manager core elements - Vacation Definition