はは/haha, (not ほほ/hoho) and お母さん/okaasan/okasan are both correct words for "mother."母
To explain one way simply, it has to do with politeness; "okaasan/okasan" would be used when referring to someone elses mother, whereas "haha" would only be used when referring to one's own mother.
I just want to add, that when directly addressing your own mother, you use お母さん（おかあさん）FalconKrunch
Commented 8 years ago