If you describe someone as helpful, you mean that they help you in some way, such as doing part of your job for you or by giving you advice or information.
The staff in the branch office are helpful but only have limited information.
该分支机构的员工很帮忙,但他们所知的信息有限。
If you describe information or advice as helpful, you mean that it is useful for you.
The catalogue includes helpful information on the different bike models available.
该目录包含所销售的各种型号自行车的有用信息。
Something that is helpful makes a situation more pleasant or more easy to tolerate.
It is often helpful to have your spouse in the room when major news is expected.
等候重大消息时,有配偶一起在场往往会好些。