Arduino Uno is a complete development board of microcontroller ATmega328. It is most commonly used Arduino because of compact size, number of input output pins, price, availability etc. It has 14 Digital input output pins in which 6 pins provide PWM outputs and 6 Analog output pins. It has everything that a general Arduino based project need.
Basics Components on Arduino Uno Board:
14 Digital and 6 Analog output pins
A crystal oscillator of 16 MHz to provide 16MHz clock speed
To power it has a USB connection and a power jack
ICSP header and
A reset button to upload new or reload the programme
Arduino Uno R3 Board Programming
The most common way to program Arduino Uno is Arduino IDE software
The microcontroller in Arduino Mega, Atmega328 comes preburned with bootloader because of that anyone can burn or upload new code without any external hardware programmer and communicates using original STK500 Protocol.
Arduino, Boards and Programmer, Modules, Sensors and Modules
