Cloud service refers to the delivery of computing services—including servers, storage, databases, networking, software, and more—over the internet (the cloud) on a pay-as-you-go basis. Rather than owning physical hardware or infrastructure, users can access and use these resources remotely from cloud service providers. Key characteristics of cloud computing include: On-Demand Self-Service: Users can provision and manage computing resources, such as virtual machines and storage, without the need for human intervention from the service provider. Scalability: Cloud services can scale up or down based on demand, allowing users to easily adjust resources to accommodate fluctuating workloads. Resource Pooling: Computing resources are pooled together and shared among multiple users, allowing for more efficient use of infrastructure and cost savings. Elasticity: Cloud services can automatically scale resources up or down in response to changing demand, ensuring optimal performance and resource utilization. Measured Service: Cloud usage is typically metered and billed based on consumption, allowing users to pay only for the resources they use. Cloud computing can be categorized into three main service models: Infrastructure as a Service (IaaS): Provides virtualized computing resources over the internet, including virtual machines, storage, and networking infrastructure. Platform as a Service (PaaS): Offers a platform allowing customers to develop, run, and manage applications without the complexity of building and maintaining the underlying infrastructure. Software as a Service (SaaS): Delivers software applications over the internet on a subscription basis, eliminating the need for users to install, maintain, and update software locally.