Discord

Discord is a messaging service that has millions of users. Discord has public chatrooms called "servers", which has channels, all with different topics. Admins of certain servers can manage and customize their servers. Users that are not used by real people and operate by command are called bots, and sends something if a command is made. It uses voice chat (VoIP), which can be created as a channel in a server and by making a call in groups/private messaging. It is available online, but is also downloadable as a program for Windows, macOS and Linux, and is also available as an app for iOS and Android.