NetworkManager is the default networking suite for Ubuntu. It is a set of co-operative tools developed by GNOME. The NetworkManager service can be controlled using the nmcli tool (Network Manager Command Line Interface) as well as by its GUI.

NetworkManager is a networking toolkit installed by default in Ubuntu. It consists of a daemon running as root, network-manager, and a front end, network-manager-gnome (or plasma-nm).

The NetworkManager daemon attempts to make networking configuration and operation as painless and automatic as possible by managing the primary network connection and other network interfaces, like Ethernet, WiFi, and Mobile Broadband devices

NetworkManager will only manage connections not specified in /etc/network/interfaces

Whether WiFi, wired, 3G, or Bluetooth, NetworkManager allows you to quickly move from one network to another: once a network has been configured and joined once, it can be detected and re-joined automatically the next time its available.