MSKSEMI AMS1117-5.0V

The rated output current is the maximum load current that a power supply can provide at a specified ambient temperature. A power supply can never provide more current that it's rated output current unless there is a fault, such as short circuit at the load.

Dropout voltage is the input-to-output differential voltage at which the circuit ceases to regulate against further reductions in input voltage; this point occurs when the input voltage approaches the output voltage.