Arduino Uno is a microcontroller board based on the ATmega328P. It has 14 digital input/output pins (of which 6 can be used as PWM outputs), 6 analog inputs, a 16 MHz quartz crystal, a USB connection, a power jack, an ICSP header and a reset button. It contains everything needed to support the microcontroller; simply connect it to a computer with a USB cable or power it with a AC-to-DC adapter or battery to get started.. You can tinker with your UNO without worring too much about doing something wrong, worst case scenario you can replace the chip for a few dollars and start over again.
Specifications:
Microcontroller :- ATmega328P
Operating Voltage :- 5V
Input Voltage (recommended) :- 7-12V
Input Voltage (limit) :- 6-20V
Digital I/O Pins :- 14 (of which 6 provide PWM output)
PWM Digital I/O Pins :- 6
Analog Input Pins :- 6
DC Current per I/O Pin :- 20 mA
DC Current for 3.3V Pin :- 50 mA
Flash Memory :- 32 KB (ATmega328P) of which 0.5 KB used by bootloader
SRAM :- 2 KB (ATmega328P)
EEPROM :- 1 KB (ATmega328P)
Clock Speed :- 16 MHz
LED_BUILTIN :- 13
Length :- 68.6 mm
Width :- 53.4 mm
Weight :- 25 g