Heat sink draws heat away when applied to a component. In electronics, heat sink compound is generally used to thermally bond a component with a mechanical heat sink. For electrical applications, it is used with thermocouple wells, thermistors, and calrods, or wherever efficient cooling is required.
Silicone Free Heat Sink
Heat-sink for electronics, avoid silicone contamination
Transistor Silicone Heat Sink Grease
Heat sink compound for electrical applications