Install dbus-1-doc by entering the following commands in the terminal:
sudo apt update sudo apt install dbus-1-doc
simple interprocess messaging system (documentation)
D-Bus is a message bus, used for sending messages between applications. Conceptually, it fits somewhere in between raw sockets and CORBA in terms of complexity. . This package contains the API documentation for D-Bus, as well as the protocol specification. . See the dbus description for more information about D-Bus in general.