A bridging visa (BVA) is a temporary visa which allows you to stay in Australia in the instance that your first year visa expires and your second year visa still hasn't been granted. If you are on a bridging visa for two months whilst waiting for your second year visa to be granted, those two months will be deducted from your second year. As long as the last visa you held in Australia was a Working Holiday Visa, you can still work whilst on a bridging visa.