Dear sir, what is difference between flagyl and vermox?

Very different: Flagyl is an antibiotic used to treat bacterial infections. Commonly used for infections that involve gut bacteria or infections in pelvic region, including some STD's. Vermox in an antihelminthic medication, which means it treats parasites, mainly worms of various types. We don't have lots of worm infestations in the U.S. except for pinworms, but worldwide worm infections are common.