Friendship - what is it?

I was walking through the store the other day and paused to look at something that caught my eye. Not something I liked or would consider buying, but something that caught my eye because I thought my friend would like it. It's interesting how often that will happen. Makes a person ponder just what friendship is. There are a lot of things that claim to define friendship, but I suppose it's different to everyone really.

I know someone that thinks it makes for best friends to go up to a couple of years between talking to one another. Another person I know (who is one of my two best friends) I talk to every day and if I don't see her online she calls me on the phone to make sure everything's okay. Two extreme views on friendship. But it's more than that. It's an indefinable quality that just makes that person a special part of your life. A connection without which you would not feel complete. It don't matter how far apart you are, only that the connection is there.