Grandmother — a polite or affectionate term for one's own or someone else's grandmother.
おばあさんの作るおにぎりはとてもおいしい。
The rice balls my grandmother makes are very tasty.
お祖母さんに電話して元気かどうか確かめた。
I called my grandmother to check how she was doing.
祭りでおばあさんが昔話をしてくれた。
An old woman told old stories to us at the festival.
An old woman; a female senior citizen — used to refer to elderly women (not necessarily one's grandmother).
あの店にはいつもおばあさんが一人で座っている。
An old woman is always sitting alone at that shop.
道でおばあさんが重い荷物を持っていたので手伝った。
An old woman was carrying heavy bags on the street, so I helped her.