ours is a possessive pronoun used to refer to a thing or things belonging to or associated with the speaker and at least one other person. It is typically used to refer to a group of people when the speaker is also included among them.
ours is a pronoun, thus it takes the role of nouns and other pronouns. Ours should be used when referring to things that belong to the speaker or group that the speaker is connected to. Ours should never be used to refer to the possessions of a single individual.
1. That house is ours - it's been in the family for generations.
2. We won't compromise on our demands - they're ours and we won't budge.
3. Ours is the kind of friendship that will last a lifetime.
Ours should be used only when referring to the speaker and at least one other person It is often confused with 'my' which is a possessive pronoun used to refer to a single person or thing.