Originally fanzines were hand-drafted or typed on a manual typewriter and printed using primitive reproduction techniques (e.g., the spirit duplicator). Only a very small number of copies could be made at a time, so circulations were extremely limited. The development of Roneo and mimeograph machines enabled higher numbers to be run off, and the photocopier increased the speed and ease of publishing once more. Today, thanks to the advent of desktop publishing and self-publication, there is often little difference between a fanzine and an official magazine.
One peculiarity about fanzines is that many communities have developed them independently, and they all claim to have invented the fanzine. There are science fiction fanzines, anarchist fanzines, inline skating fanzines, etc. They have different focuses and appeal to different audiences, but they all meet the basic criteria for zinedom - the urge to express yourself and to share information with your peers.
The tradition of amateur journalism is an important precursor to fanzines. There exist today communities of science fiction fans who form amateur press associations (APAs) and contribute to a collective fanzine called an apazine which contains contributions from all of them.
The first fanzine came from science fiction fandom and was published in 1930 (The Comet by the Science Correspondence Club). In SF fandom, many if not most science fiction fanzines are published without intending to make money and are given away to anyone who asks for them. Many fanzines are available for "the usual", meaning that you need to ask for it to get it. If you want to receive further issues, it's a good idea to send a LoC (letter of comment) about it to the editor. The LoC might be published in the next issue, in whole or in part. It was not unusual, especially in pre-Internet-times, that fanzines consisted almost exclusively of letter columns where debates where conducted in much the same way as they are in newsgroups and mailing lists today, but at a glacial pace in comparison.
The Punk explosion in the United Kingdom lead to a massive upsurge of interest in fanzines as an alternative to the mainstream media that was felt to be too exploitative, capitalist, and essentially disinterested in the Punk Movement and the concerns of disaffected youth. The first and perhaps still best known UK 'punkzine' was Sniffin' Glue, produced by Deptford punk fan Mark Perry, which ran for 12 issues between 1976 to 1977.
The appearance of the photocopier allowed fanzines to be easily reproduced and thus more widely distributed. The Punk influence of depreciating aesthetic or intellectual qualities and instead placing great emphasis on the importance of enthusiasm and the rejection of apathy by "doing" something has endured in the decades after the substantial decline of Punk. The influence of Punk zines in traditional science fiction fanzines, whilst noticed, has been minimal.
The aesthetic qualities of fanzines have improved with the introduction of the computer - and traditional science fiction fanzines have always emphasized intellectualism. Fine writing in science fiction fanzines remains their most important attribute, with science fiction fans valuing the written content of a fanzine as its most important attribute. (In this respect, Punk fanzines have had little impact on traditional science fiction fanzines.)
In the United Kingdom role-playing fanzines allowed people to communicate in the 1970s and 1980s with complete editorial control. These early fanzines were generally typed, sold in an A5 format and were often illustrated with abysmal or indifferent artwork. A fanzine community developed and was based on sale to a reading public and exchanges by editor/publishers.
In recent years the traditional paper zine has begun to give way to the webzine (or "e-zine") that is easier to produce and uses the potential of the Internet to reach an ever larger, possibly global, audience. Nonetheless, many people are still producing paper fanzines, either out of preference or to reach people who don't have convenient Web access. One example of a zine is The Inner Swine