Infrastructure-as-a-Service<\/a> (IaaS) is a fundamental Cloud-Computing<\/a> delivery model that provides virtualized computing resources over the internet. In this model, a third-party provider hosts Servers<\/a>, Storage<\/a>, and Networking<\/a> components on behalf of its users. Major global providers include Amazon-Web-Services<\/a>, Microsoft-Azure<\/a>, and Google-Cloud-Platform<\/a>. This service model allows for high Scalability<\/a> and significantly reduces the need for upfront Capital-Expenditure<\/a>.<\/p> According to Gartner<\/a>, IaaS is a highly automated offering where compute resources are owned and hosted by a service provider and offered to customers on-demand. Users typically interact with these resources using Application-Programming-Interfaces<\/a> or web-based consoles. The Virtualization<\/a> layer is the core technology that enables the creation of multiple Virtual-Machines<\/a> on physical hardware. For further technical insights, see the IBM guide to IaaS<\/a>.<\/p> Security within the IaaS framework is typically managed through a Shared-Responsibility-Model<\/a>, where the provider secures the physical infrastructure and the Hypervisor<\/a>, while the customer is responsible for the Operating-System<\/a>, applications, and data. This structural division is a critical component of modern Cloud-Security<\/a>. Organizations like NIST<\/a> provide standardized frameworks to help categorize these cloud services.<\/p>