NickServ facilitates nickname access controls which prevents users from maintaining control over another user's nickname.  Nickname registration is completed through the MajorNelson website, at which point registration will propogate over to the IRC server.  ChanServ allows all users on the network to register and maintain their own channels.  HostServ allows users to request appropriate vHosts.  BotServ allows channel owners to bring a services bot onto the channel which integrates with ChanServ's access controls and performs typical bot functionality, such as kicking flooding users.