What do Friends do? They hold space for each other – space for silliness, doldrums, reaching out for a hand up, to hang in there, and a hug. They give each other a hand to paint that room, get into some shenanigans and laugh, or cry, or laugh till you cry, cry till you laugh together! Space to be still and silent without asking "Why did you come to be here?" In this space Friends listen, converse, and share the conversation and investigation of the territory of the heart. Because they can.
And yet as Gilles Dahan commented once in Social Media, I can know you without knowing you!
How do you folks define 'Friend' as opposed to acquaintance?