Grandma (ā má) generally refers to her own mother in Taiwanese, and can also be used to address the other's mother, which is equivalent to the usage of "aunt". In addition, grandma can also be used to address grandma, or older women such as wives and old women.
Mother (ā mǔ) generally refers to her own mother in Taiwanese, but this title is usually used in more formal occasions or literary works. In addition, grandmother can also be used to refer to ancient musicians, female teachers or pimps in brothels.
It should be noted that grandma and grandma in Taiwanese are not the same word, and their usage and meaning are different.