I'm only going to reply with my offline friendships in mind.
I have a pretty strict definition of friendship. Offline, I put a lot more into my relationships with other people than I do online. I'm okay with being alone, and I prefer it most of the time, but I'm human and need social interaction outside of work and those are far and few in between. I want a like-minded individual to be able to mutually share experiences with, good times, and laughs, as well as hardships and character defining moments. I want to be able to support them and I want them to be able to support me if needed. Unfortunately, I don't have many people who are as emotionally and mentally involved in the "friendship" we share, and therefore, I don't really consider them a friend. Though, I'm sure many people can say that about me.
Right now I only have two friends offline: Sarah and Paige. Paige I met at marching band sophomore year of high school, I believe. We didn't really talk much until my senior year and onwards. We didn't become friends until after I graduated, but we had a few conversations during the time that we started talking and I thought she was really cool and would be a fun person to be around. She's the person I hang out with the most. Sarah, I met at my first job at CVS. We were hired at the same time, and we hung out a lot after we started talking. At the time, I also had a friend named Chris (who is currently her boyfriend because I kind of played matchmaker, and I don't really talk to him much since he's not the greatest texter if you know what I mean) and the three of us hung out about two or three times a week and all Saturday most of the times. We had early morning diner trips and late night park adventures. Sarah is currently my best friend offline, but we don't hang out much and she's really, really flakey, which disheartens me.
Also, recently, my frame of minds and values have shifted drastically, and I'm reconsidering my relationships with other people because of that. I'm very much interested in meeting new people and forming a circle of about three or four other people that would be my friendship circle. I envision we'd do practically most things together and we'd hang out as much as we could. I've wanted a friendship group since I was in high school, but never really fit into one particular clique. I kind of drifted between and didn't take the opportunity to develop those relationships to possibly form genuine friendship with them. They were just school friends, to me. People I would hang out with strictly at school. Throughout my school life, I probably had less than ten friends that I hung out with regularly outside of class.
I have plenty of people I'm friendly with and am on friend-like terms with, and I also have my fair share of work friends. I'm sure they consider me their friend if they were asked, but I don't really consider them to be mine because of those reasons. The phrase, "If you have two friends in your lifetime, you're lucky. If you have one good friend, you're more than lucky." comes to mind when I think of friendship. Good friends are what I define as friends, and I've only had a few of them in my lifetime.