Developed since July 2004, a ZNC é uma BNC - Bounced Network Connection - which is a program that retransmit a connection from a client, in this case, an IRC Client to an IRC Network 24 hours a day , 7 days a week - 24/7. The client can disconnect from ZNC and still be connected to the IRC server. BNC is the original program. After him came psyBNC and several others. Currently one of the most known is ZNC. Boucers give their users privacy and security, hide the origin of their connection and their host/IP and also protect their messages. However, security and privacy are just some of the benefits of a Bouncer. They also have several modules that propose a lot of functions to their users and their IRC clients. In the past we heard a lot about how to install a Bouncer, first we need a Shell account. In fact, a Shell account is necessary, but it is nothing more than a user account on a server that is running a UNIX-Like-based system, such as Linux. The basic differences between a BNC, psyBNC and a ZNC, are due to the modules that each one has.