Glossary of Terms:
 
unbalanced
A type of connection between electronic devices, using shielded, single-conductor cable. With this connection, the signal path is sent down the wire and back through the shield which is connected to ground. This method is more susceptible to interference than using a balancedconnection.
Source: Yamaha

Also refered as:
  high impedance
Related terms:
  1/4-inch jack   XLR connector   balanced   balancing   input   low impedance   output