It's "avoir" which means to have, it agrees with gender and plural of a noun ex :I have a book :" J' ai un livre" and we have a book : " Nous avons un livre "
It depends on who the owner is. Has is part of the French verb "Avoir" (to have) which is irregular so how you say it depends on the number of people, and the gender you are talking about (just like in English).
I (ai)
you (a)
he/she (a)
We (avons)
You (plural) (avez)
They (ont)
I (ai)
you (a)
he/she (a)
We (avons)
You (plural) (avez)
They (ont)