Sysop is a neologism formed from the words 'system' and 'operator.' It is typically a title employed by a person responsible for the moderation or administration of virtual communities, like discussion forums or bulletin board systems (BBS). A sysop typically has a measure of administrative powers with which to manage the community. Sysadmin, or system administrator, is a similar term that typically refers to a professional position. While both titles refer to someone with administrative powers and responsibilities in some type of networked computer system, a sysop typically donates his time, or is part of the community in question.
While sysop may be a relatively new term, the title 'system operator' has long referred to anyone who manages a complex computer system, like a mainframe. As the electronic BBS became popular, the term was borrowed to refer to the administrators of those systems. Members of the community would often be named co-sysops and receive certain powers and responsibilities. BBS co-sysops were sometimes tasked with things such as managing files on the server, handling new members, and moderating discussions.
A wide variety of virtual communities across the Internet utilize sysops in some function. Many of these groups are formed around discussion forums and other sites that encourage user contributions. Due to the fact that most of the content on these sites is user-generated, sysops will often have the task of moderating it for content. They will also often handle back-end tasks involved in monitoring and maintaining the software that the community runs on.
Internet Relay Chat (IRC) may also use the term to refer to users with moderating power. These users, also known as channel operators, are generally able to change certain aspects of a chat room, remove abusive users, and perform a variety of other functions. IRC also has a number of other positions that grant higher authority over the IRC server, such as the IRC operator (IRCop) that may possess broad powers to ban users and alter channels.
Sysadmins may perform many of the same functions as sysops, but are typically also responsible for the administration of network servers or hosts. A system administrator is also usually a paid position held by a professional, while a sysop is generally an unpaid volunteer. The owner or operator of an Internet forum will often be referred to as an admin, though this is not necessarily the same as a sysadmin. While the sysadmin often has root access to the server and control the software the community runs on, he may or may not be responsible for the hardware or be a paid professional.