How Event 'CREATE' gets trigger
i would like to know how event 'CREATE' gets trigger when i save some documents .
say for example when i save sales order document in 'VA01' how workflow gets trigger backend by help of 'CREATE' 'BUS2032' because if you see the function code for 'SAVE' button in VA01 that will different then BOR event 'CREATE' then how it is getting trigger.
i want to know where is the relationship between Workflow event 'CREATE' and VA01 'SAVE' button.
please help me to out of this .