LEDs are "light emitting diodes", able to efficiently convert electricity to light without the need for a filament or phosphor. LED light strings use a fraction of the electricity of incandescent light strings, last longer, and the bulbs remain cool to the touch.

The primary difference between residential strings and commercial strings is the packaging (residential strings come in retail packaging while commercial strings are simply in bags) and the fact that residential strings are longer, but every residential string has it's own plug, while commercial strings have special "locking" connectors to allow long lengths of multiple strings to be strung together without a chance that they can disconnect. Both may be used for either interior or exterior applications.