One of the coolest things about many electronic components is that they are reversible. For example, if you send electric power to a motor it will spin. If you instead turn the spindle, it will create electricity. The same concept is true for LEDs. If you send power through them, they light up. If you shine light at them, they will produce electricity.

I’m not sure what I want to do with this information, but it’s fascinating to me that these components are able to be opposites depending on how they are used.