Meaning – The term networkmanager, refers to a program or group of programs that are used to monitor, manage, and diagnose the problems of a network.
It also refers to a daemon that sits on top of libudev and other Linux kernel interfaces (and a couple of other daemons) and provides a high-level interface for the configuration of the network interfaces.
To connect computers with each other, various communications protocols have been developed, e.g. IEEE 802.3 (Ethernet), IEEE 802.11 (“wireless”), IEEE 802.15.1 (Bluetooth), PPPoE, PPPoA, and many many more. Each participating computer must have suitable hardware, e.g. network card or wireless network card and this hardware must be configured accordingly to be able to establish a connection.
Example of usage – “Network Manager takes an opportunistic approach to network selection, attempting to use the best available connection as outages occur, or as the user roams between wireless networks. It prefers Ethernet connections over “known” wireless networks, which are preferred over wireless networks with SSIDs to which the user has never connected.”