UNO R3 SMD
The Arduino UNO is the best board to get started with electronics and coding. If this is your first experience tinkering with the platform, the UNO is the most robust board you can start playing with. The UNO is the most used and documented board of the whole Arduino family.
Arduino UNO SMD 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 ceramic resonator, 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.
The "SMD" stands for surface-mount device, and the microcontroller (ATmega328p) is soldered directly to the board.
The classic high-performance, low-power AVR® microcontroller.
The ATmega328P also features 1kb of EEPROM, a memory which is not erased when powered off.
The Arduino UNO features a barrel plug connector, that works great with a standard 9V battery.