|Let KNetworkManager handle your open and encrypted connections.|
KNetworkManager is a KDE client for the back end NetworkManager software. KNetworkManager communicates with NetworkManager via DBus (a type of message passing software).
One typical usage is to connect to a wireless network with credentials known to the user. The user will setup a connection and KNetworkManager will store the settings wherever the user's configurations are stored. The configuration will include things like the name (ESSID) and passphrase used to associate with a particular wireless network. KNetworkManager can then use this information by packaging it into a DBus request to connect to a particular network. The Network Manager back end then does the low level operations required to actually setup the support software (e.g. pushing ESSID and key to wpa-supplicant) and bring up the network device with the appropriate settings.
Along with the advantage of allowing normal users to control the configuration the network it also allows one consistent interface for network configuration on KDE, and other desktops (e.g. GNOME) can use the network manager back end without each having to implement the logic to handle network configuration.