Cloud computing, Fog computing, and Edge computing are three interconnected paradigms that support modern distributed systems, especially in the context of the Internet of Things (IoT). They differ mainly in terms of location of computation, latency, resource availability, scalability, and use cases. Together, they form a hierarchical architecture that enables efficient data processing, storage, and decision-making from end devices to centralized data centers. Cloud computing refers to the delivery of computing services such as servers, storage, databases, networking, analytics, and software over the internet. In cloud computing, data generated by devices or applications is transmitted to centralized data centers where large-scale processing and storage occur. The cloud provides virtually unlimited computational resources and storage capacity. It supports service models such as Infrastructure as a Service (IaaS), Platform as a Service (PaaS), and Software as a Service (SaaS). Cloud computing is highly scalable and cost-effective due to its pay-as-you-go model. However, because the data must travel long distances to centralized servers, it introduces higher latency. This makes it less suitable for time-sensitive applications such as autonomous vehicles or industrial automation where real-time responses are critical. Fog computing acts as an intermediate layer between cloud and edge devices. It extends cloud capabilities closer to the network edge by deploying computing, storage, and networking resources at local nodes such as gateways, routers, or micro data centers. Fog computing reduces latency by processing data closer to the source while still maintaining connectivity with the central cloud. It is particularly useful in IoT environments where massive data is generated continuously. Instead of sending all raw data to the cloud, fog nodes can filter, aggregate, and preprocess data