It stands for In-Circuit Serial Programming. Crystal Oscillator- The Crystal oscillator has a frequency of 16MHz, which makes the Arduino UNO a powerful board.The Vcc voltage value can be negative or positive with respect to the GND pin. It is also called as the primary voltage for IC's present on the Arduino board. It is the modulated DC supply voltage, which is used to regulate the IC's used in the connection. The save line in the MISO pin is used to send the data to the master. It stands for Master Input/ Slave Output. These are the clock pulses, which are used to synchronize the transmission of data. It is used to add a Reset button to the connection. It is essential for the programming of the Arduino UNO board. It allows the board to connect to the computer. The USB Interface is used to plug-in the USB cable. It also represents the successful flow of data. The TXD is used for transmitting the data, and RXD is used for receiving the data. TXD and RXD pins are used for serial communication. The ground pins are used to ground the circuit. For any changes in the input voltage of the regulator, the output voltage is constant and steady. The primary function of voltage regulator is to regulate the voltage level in the Arduino board. The voltage regulator converts the input voltage to 5V. The Arduino UNO and Nano models are based on the ATmega328 Microcontroller. It is a low-cost, low powered, and a simple microcontroller. The processor core inside it is of 8-bit. ATmega328 Microcontroller- It is a single chip Microcontroller of the ATmel family.The Arduino UNO Board, with the specification of pins, is shown below: It is easier to use than other types of Arduino Boards.

The Arduino UNO is a standard board of Arduino, which is based on an ATmega328P microcontroller.

Arduino board uno datasheet