SCR - A semiconductor which is made from silicon used to convert AC power to DC which can be used to control or rectify AC power semiconductors.
Diode - A semiconductor which allows electric current to flow easily in one direction but not in the other.
Rectifier - A semiconductor used to convert AC power to DC. It allows current to flow in one direction and prevents the flow of current in the opposite direction.
Discrete Device - An individual electrical component packaged or unpackaged, such as a resistor, capacitor, transistor, diode, etc.
Heat sink - A material with good heat conducting or dissipating properties to which a packaged device is attached to cool and maintain the output semiconductor junctions within the rated temperature range.
Trigger - To turn on an SCR utilizing its gate.
Thyristor - A term for the general class of semiconductor devices which includes SCR's, triacs, alternistors, etc.
Anode - Positive terminal of an SCR or Diode. Positive with respect to cathode and or gate terminals.
Cathode - Negative terminal of an SCR or Diode with respect to the anode.