I'm learniglearning Arduino. I use Arduino Uno board with ATMEGA328-PU. I tried basic codes like LED blink, control of DC motor etc. Arduino board is used only when we program microcontroller, right? I mean, when we finish programming it, we can use microcontroller separately? If it can be used separately, we must have some "external" circuit as replacement for Arduino board, which allow us to use microcontroller in specific application. What type of circuit is used? I'm new in this field so don't blame me because of amateur questions :).