what criteria do you use to determine if someone is a friend of yours?

Hmm, my definition changed over a bit. First i considered internet friends not to be real but now I do. It just didn't match my former definition.

My former definition was: you have to helped each other ones or have done something together. An event like swimming or attending to smth. People you can always call despite how long you didn't talk to to them are good friends too. Friends don't have an expiry date imo.

Internet friends are possible since they can provide information that help you or giving interesting insights giving them value for you.

If not friend, why friend shaped?

No idea. I haven't got enough time for friendships anyway, so why bother

I don't have friends, so it's easy.

I've been told they're important, but they always turn into sources of stress and liability. Maybe it's the area I live in or something to do with my upbringing that attracts those kinds of people. I don't know. I'm old enough that it's not something that bugs be anymore.

I am friendly with coworkers, but they and I cease to exist when they leave the office, so calling them friends would be too much.

Im not sure, I just know. There's only a handful of people I consider true friends. It's usually people that don't want anything from me, because they are all skilled people. So if they actually do need something from time to time im actually happy to help. I never felt the emotion of wanting to help someone completely selflessly around people I don't consider friends. But as for what the criteria is Im not sure, probably intelligence, self sufficient, not a snowflake, good humor... Something like that