HOLLYOAKS, Max & Tom?

hollyoaks has been SO SO SO sad it's made me cry loads! but i just want to know the relationship between max, tom and cindy? because i thought max and tom's parents both died? but cindy was their step sister? and her mum was at max's funeral? are max and tom half brothers and it was max's step dad that died? or... what? i don't get it. can someone tell me it's bugging me lol! thanks x