How do channels work in game?
Through the channels you can communicate with other players that are online. There are two channels open by default when you start the client for the first time: Local system and the Corp channel.
Channels are instant communication devices, sorted by category. The channels created by your character will be listed in the "My channel" tab, while all custom channels you added remain in the "Player channels".
Press the "Join" button to subscribe to either a channel or mailing list and update the panel. To leave a channel, open a tab, right-click the channel line then select "Leave channel". Once it is done, right-click the line and select "forget channel" to completely remove it.
See also: Cant see anything on a chat channel