One is active, one is passive. Both are forms of the past perfect tense. He has done his homework = he did it, it is now complete His homework has been done = the homework was completed, but with the emphasis on the homework rather than him By making the object of a sentence the subject you turn it into the passive which emphasises more the action than the person doing it.

"Has done" is used when talking about what someone has done. "Has been done" is used when talking about a thing that has been done. For example... Huili has done her homework. The project has been done (by Huili). "Has been done" can also be used with a period of time. For example... The project has been done for two weeks.

has done = active voice has been done = passive voice