Our is the possessive form of "we." It shows that something belongs to “us” or is related to “us” (e.g., our sister, our computers).
Our house is on fire!
We were so tired after our three-hour workout.
Are is the present tense of the verb “to be.” It shows some state or action that is occurring in the present related to "you" or to a group of people or things.
You are my hero.
They are so good at surfing!
Are is also used in questions:
Are there any doughnuts left?
Are we there yet?