An LED has two potential customers: the anode (positive) as well as the cathode (detrimental). It is essential to attach the LED the correct way all over inside a circuit—LEDs are polarized elements, and reversing the polarity will prevent them from Performing. The expression 1st appeared inside the English language https://www.uk-exhibitionstands.co.uk/future-of-exhibitions-key-trends-for-the-next-5-years/