Arduino is an open-source electronics platform widely used in IoT and cloud computing laboratories for prototyping embedded systems and smart devices. It consists of a microcontroller-based development board and an integrated development environment (IDE) that allows users to write, compile, and upload code to the board. In IoT laboratories, Arduino serves as a fundamental building block for sensing, data acquisition, and device control applications. The core of an Arduino board is a microcontroller, such as the ATmega328P in Arduino Uno, which executes programmed instructions. It provides digital input/output pins, analog input pins, power pins, and communication interfaces such as UART, SPI, and I2C. These interfaces allow Arduino to connect with sensors, actuators, displays, and communication modules. For example, temperature, humidity, light, motion, and gas sensors can be interfaced to collect environmental data, while relays, motors, and LEDs can be controlled based on programmed logic. In IoT laboratory setups, Arduino is typically used as an edge device that collects real-time data from physical environments. Since it operates with low power consumption and simple hardware requirements, it is ideal for building sensor nodes. The analog-to-digital converter (ADC) inside the microcontroller converts analog signals from sensors into digital data, which can then be processed or transmitted. For cloud integration, Arduino can be connected to the internet using additional modules such as Wi-Fi (ESP8266 or ESP32), Ethernet shields, or GSM modules. Through these communication modules, Arduino devices can send sensor data to cloud platforms such as AWS IoT, Microsoft Azure IoT Hub, or Google Cloud IoT Core. Data is typically transmitted using lightweight communication protocols such as MQTT or HTTP. Once the data reaches the cloud, it can be stored, analyzed, visualized, or used to trigger automated actions. The Arduino IDE simplifies programming through a user-friendly interface and a C/C++-based language. Libraries are available for various sensors and communication modules, reducing development complexity. In laboratory environments, students use Arduino to understand core IoT concepts such as data acquisition, real-time processing, device communication, and cloud connectivity. However, Arduino has limitations in terms of processing power, memory capacity, and multitasking