Why do need to give the application name at both places in Concurrent executable and cocurrent program definition form?

Executable :-

At the time of Creating an Executable , Application Name is Mandatory Because  System will refer the Execution file top where we have Kept source file means under which top of OS Level or in DB Schema level .
Generally we will give Custom Application Name at the time of Creating Custom Executable

Concurrent Program :-

At the Time of Creating an Concurrent Program Application Name is Mandatory here you may give Application name other than your Executable Application name , while submitting of your Concurrent Program from SRS Window Internally Application Id will Pass Associated with its concurrent program, that is the Reason we are Passing Application short name when we Submit the Request from Back end using FND_REQUEST.SUBMIT_REQUEST.