两者都有help的意思
帮助: means:to help ; to assist ; to aid ; to support ; to boost ; to back up ; to bear a hand ; to minister to ; to take an oar ; to do somebody a service help ; ministration ; charity ; a boost ; assistance
in chinese means:以出钱、出力或出主意的方式相助别人,替人出力、出主意或给以物质上、精神上的支援。
帮忙:means:1.to help; to give a helping hand; to do a favor; to do a good turn; to lend a hand; to oblige
2.assistance; offices
in chinese means:帮助别人做事或解决困难
ex:我可以帮忙做这件事。
我可以帮助你做这件事。
Both of them can used as a verb,and 帮忙can used as a none.
But, in general,帮忙in oral chinese can`t add sb(somebody).