The Arduino UNO is a development board which features the ATmega328P microcontroller (MCU). It is a perfect introduction to electronics and coding. The UNO also demonstrates the basics on sensors and actuators. The UNO is the ideal, entry-level board for those who are new to developing on the Arduino platform. It’s a popular board as it is really robust when it comes to tinkering. For those more experienced, it’s still the perfect board for rapid prototyping. 

How simple is it?

Very. The board contains everything it needs to support the ATmega328P MCU. Just connect it to PC via USB cable or connect it to an AC-to-DC battery. The Arduino Software (IDE) is there to help but the UNO is a sturdy board. You can tinker to your heart’s content without having to worry too much about breaking it. And, if something does go wrong, you can always replace the chip. 
There is also a community surrounding Arduino which is there with lots of support. So, if you’re ever stuck, just reach out for help. There is also tonnes of resource to help inspire you with your next project. https://www.arduino.cc/ 

What else is on-board?

ATmega328P Microcontroller 14 x digital I/O pins (6 can be used as PWM outputs) 
6 x Analogue inputs 
16MHz quartz crystal 
1 x USB 
1 x power jack 
1 x ICSP header 
1 x reset button 

Operating voltage: 5 V FLASH memory: 32 KB 
SRAM: 2 K 
EEPROM: 1 K 
Size: 68.6 x 53.4 mm 

What is Arduino?

Arduino is an open-source electronics platform consisting of hardware and software. Every aspect is designed to be straightforward so you can learn to code or design a project, quickly and easily. It’s designed for students, programmers, designers, hobbyists and tinkerers. The Arduino open-source software (IDE) is there to help too. It makes is much easier to write code and transfer it to your board. 

Note

USB Cable and battery are not included.