The one file that builds up the CJT Packages. Just like using User Interface for creating Blocks or Templates. User has to click ‘New’ button, Fill the Form, click save and Link Block to Templates if needed. The same operations can be done by writing few keywords to the definition.xml file that CJT Package installer would carry instead of users.
definition.xml file is defining a few XML Tags that can be used to tell CJT what operation should take. The file is processed by the same order from Top to Bottom.
The definition file must be exists in the package root folder otherwise the CJT Installer would fail.