The power pins of an Arduino board include the following.

The battery terminals can be placed in the pins of Vin as well as GND. The connection of an adapter can be done by plugging a center-positive plug (2.1mm) into the power jack on the board. The exterior power supply (6 to 20 volts) mainly includes a battery or an AC to DC adapter. The power supply of the Arduino can be done with the help of an exterior power supply otherwise USB connection. This board includes 14 digital input/output pins, Analog inputs-6, a USB connection, quartz crystal-16 MHz, a power jack, a USB connection, resonator-16Mhz, a power jack, an ICSP header an RST button. From these pins, 6-pins can be utilized like PWM outputs. The Arduino Uno R3 pin diagram is shown below.

The recommended input voltage ranges from 7V to 12V.The Operating Voltage of the Arduino is 5V.It is an ATmega328P based Microcontroller.