Arduino is a very popular microController for newbies. It is easy to use and opensource, which makes it all the more easier for electronic enthusiasts to learn and make it their new hobby. We will learn about the components on the Arduino and their functions. Most of the Arduino’s have a lot in common. So below is a list of the following :

1	USB Female Port – Arduino can be powered using the USB cable. The same USB can be used to upload the Code from the computer using the Arduino IDE
2	Power Barrel Jack – This jack can be used to power the Arduino using a battery or a DC adapter (Not forgetting the battery or DC adapter should output below 18V to be on a safer side)
3	Voltage Regulator – The regulator controls the voltage given to the Arduino Board and gets it to 5V or 3.3V as required for its usage. The voltage levels are regulated as per used by the processor and other elements.
4	Crystal Oscillator – This sets the clock on the Arduino. It helps Arduino to calculate time. The number printed on the top of the Arduino crystal is 16.000H9H, which indicates that the frequency is 16,00,000.
5	Arduino Reset – You can reset the arduino board using this button. Also, you can connect an external reset to the RESET pin on the Arduino Board.
6	3.3V – Provides a supply of 3.3V for connecting peripheral devices.
7	5V – Provides a supply of 5V for connecting peripheral devices.
8	GND – There are many Ground Pins on the Arduino. These pins can be used to ground the circuits or modules connected to the Arduino.
9	Vin – This pin is used to power up the Arduino using an external power source. (DC power)
10	Analog Pins – These pins are used to read analog signals from analog sensors (Humidity Sensor, Temperature Sensor etc) and converts it into a digital value that can be read by the microprocessor
11	MicroController – The brain of the embedded system. The microControllers used on Arduino are usually ATMEL
12	ICSP Pin – ICSP is an AVR, a small programming header for arduino with MOSI, MISO, SCK, RESET, VCC, and GND. It is referred to as an SPI(Serial to Parallel Interface), which could be considered as an expansion of the output. This concept is called
13	Tx and Rx LEDs – The TX led flashes with different speed while sending the serial data. The speed of flashing depends on the baud rate used by the board. RX flashes during the receiving process.
14	Digital Input and Output – The Arduino UNO board has 14 digital I/O pins (of which 6 provide PWM (Pulse Width Modulation) output. These pins can be configured to work as input digital pins to read logic values (0 or 1) or as digital output pins to drive different modules like LEDs, relays, etc. The pins labeled “~” can be used to generate PWM.
15	AREF – AREF stands for Analog Reference. It is sometimes, used to set an external reference voltage (between 0 and 5 Volts) as the upper limit for the analog input pins.