Each variety is worth exactly the same and results in the awarding of the same diploma, but the material is varied to ensure that it is appropriate for the target cohort. DELF is not a certificate but it is a degree valid for life and does not expire.
Every variation of the DELF program is worth the same amount and results in the same diploma, but the materials used are tailored to match the target audience.  DELF is not a certification but rather a lifelong degree that never expires.