The 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.. New starter kit uno r3 mini comes with a complete component: breadboard
leds
resistors
jumper wires
buttons
button nubs
sensors
9v battery terminal