The fundamental difference between SSR (Special Summary Revision) and SIR (Special Intensive Revision) is —
> In SSR, only those voters who want inclusion, deletion, or correction in the existing electoral roll need to apply.
While in SIR, every voter, even those already enrolled, must fill and submit the enumeration form for complete re-verification of the voter list.
In short:
👉 SSR = Summary update of existing roll
👉 SIR = Complete verification of all voters