Then, chances are you already know what an Arduino is ... notice between the two boards' pinouts are that the Nano has more reset pins (two versus one on the Uno), fewer GND pins (two versus ...

The pinout diagrams are simple, but they're easy to read, and especially helpful for beginners. You can print them out full size so you can set your Arduino Uno, ATMega, or ATTiny right on top for ...

Sure, it isn't such a big deal when you're just starting out as most professionals and experienced users recommend the Arduino Uno ... Arduino Nano and Micro share some similar pinout configurations.