Diode has a property that is ability to conduct current in only one direction. Due to this property diodes are used in rectifier circuits. As rectification is the process to convert AC signal to Pulsating DC.
To remove the AC components from a rectifier circuit a filter is used. A filter circuit is a device to remove the AC components of rectified output. A filter circuit is a combination of inductor and capacitor and is called LC filter.
This name is a representation for a device having transfer resistors. As we have seen a semiconductor offers less resistance to flow of current in one direction and high resistance in another direction