Arduino Pro Mini board is more suitable for applications and installations where space is premium and projects are made as permanent set ups. This board is a 5 V version, powered by ATmega328.The Arduino Pro Mini can be powered with an FTDI cable or breakout board connected to its six pin header, or with a regulated 5V supply on the Vcc pin. There is a voltage regulator on board so it can accept voltage up to 12VDC. If you’re supplying unregulated power to the board, be sure to connect to the RAW pin on VCC. The power pins are as follows: RAW For supplying a raw voltage to the board. VCC The regulated 5 volt supply,GND Ground pins.