Hi. I am new to Arduino, and I have little experience with microcontrollers.I have noticed that different microcontrollers technical specifications either lists a Suppy Voltage or Input Voltage and not both. What is the difference between the two attributes? Also, what is the difference between two microcontrollers that contains the opposite attributes, supply or input voltage?
Supply Voltage - the power supply pin.
Input Voltage - the High/Low level seen at the IO pins.
Should not be allowed to go more than 0.5V below Gnd or 0.5V above the Supply Voltage without risk of damaging something.