friends or acquaintance

I hear people talking about their friends but are they friends or acquaintance?

The people that I been to their home for supper/dinner and they to ours are friends.

The people I've stayed at their homes and they are ours are friends.

The people I don't know their last name are acquaintance's.

The people that stop when they need something are acquaintance's.

The people that are there when you need them are friends.