To export / import data from within AX, definition groups approach should be used.

If want to take the data backup then follow the below procedure and by means of this you can take the backup of the compnay data in which you currently working on

• Goto Administration module
• Under periodic
• expand Data export/import menu
• in that select  'Export to'
• give the location where you want to store the data

after this procedure the system will generate 2 files (DAT and DEF)