The Arduino Uno R3 is the most popular development board in the Arduino family, built around the ATmega328P microcontroller. It has 14 digital I/O pins (6 with PWM), 6 analog inputs, a 16 MHz resonator, USB connection, power jack, ICSP header, and reset button. Plug it into your computer, upload your code from the free Arduino IDE, and start building. Backed by thousands of tutorials, libraries, and shields — the best starting point whether you're learning electronics or building a serious project.