Network management on Ubuntu is handled by the NetworkManager service. NetworkManager views a network as consisting of network interface devices and connections. A network device can be a physical Ethernet or WiFi device or a virtual device used by a virtual machine guest. Connections represent the network to which the devices connect and are configured by connection profiles. A configuration profile will, among other settings, define whether the connection has a static or dynamic IP address, the IP address of any gateway used by the network and whether or not the connection should be established automatically each time the system starts up.
NetworkManager can be administered using a number of different tools including the nmcli and nmtui command-line tools, the nm-connection-editor graphical tool and the network settings section of the Cockpit web interface. In general, the nmcli command-line tool provides the most features and flexibility.