An LED has two prospects: the anode (constructive) plus the cathode (unfavorable). It is important to attach the LED the appropriate way all over in a very circuit—LEDs are polarized elements, and reversing the polarity will prevent them from Doing work. The expression to start with appeared within the English https://www.uk-exhibitionstands.co.uk/product/casonara-seg-light-box-counter-200m/