This is the 78th most frequent Hebrew word.
שלהם
"Theirs" or "their."
Here, "שלהם" denotes possession, indicating that the dog belongs to "them".
הם אוהבים את הכלב שלהם.
They love their dog.
Here, "שלהם" denotes possession, specifying that the history pertains to "them".
הוא לא מכיר את ההיסטוריה שלהם.
He does not know their history.
Here, "שלהם" denotes possession, demonstrating that the library belongs to "them".