I would like to think that most people who know me (friends and family included) have to in some part know about zines considering I've been blabbering on about them in one way or another for the past 6 years.
I've given explanations as best as I can to people when they ask about them - or show them one as reference.
There have been a lot of 'What are zine' books I've read, or online articles I've come across in my time as a zinester so I decided that I will just post some of those links below as examples for people to check out!
Wikipedia's definition of 'What is a zine' : http://en.wikipedia.org/wiki/Zine
The popular blog Rookie's explanation on what a zine is and how to make one!
The Barnard Zine Library gives an explanation from a zine of what a zine is