This is the 3rd most frequent Greek word.
της
"Της" means "her" or "of her" and is also used as the feminine singular genitive article "the."
The word 'της' is used as a possessive pronoun in the genitive case, meaning 'her.'
Αυτή είναι η τσάντα της.
This is her bag.
The word 'της' is used as an indirect object pronoun in the genitive case, meaning 'to her.'
Της έδωσα ένα δώρο.
I gave her a gift.
The word 'της' is used in a possessive construction, indicating 'her' mother.