This is the 8078th most frequent Swedish word.
yousef
"Yousef" is a male given name, equivalent to "Joseph" in English.
Here 'Yousef' is used as a proper noun referring to a person's name.
Yousef är en av mina bästa vänner.
Yousef is one of my best friends.
In this sentence, 'Yousef' again functions as a proper noun, specifically referring to an individual being asked about.
Har du sett Yousef idag?
Have you seen Yousef today?
Here 'Yousef' is used as the subject of the meeting location, again fulfilling the role of a proper noun.