A childlike, affectionate way to say grandmother; similar to 'obaachan' or 'obaasan'.
子どもが『ばあば、絵本読んで！』とせがんだ。
The child begged, 'Grandma, read me a picture book!'
週末はばあばの家でおやつを食べるのが楽しみだ。
I look forward to eating snacks at Grandma's house on weekends.
初めて会う人には『おばあさん』、親しい間柄では『ばあば』と呼ぶことが多い。
You often say 'obaasan' to people you meet for the first time, and 'baaba' among close family.