Infrastructure as a Service (IaaS) is a cloud computing model that provides virtualized computing resources over the internet. Users can rent servers, storage, and networking capabilities on a pay-as-you-go basis, allowing businesses to scale their IT infrastructure without the need for physical hardware. This flexibility helps organizations reduce costs and improve efficiency. With IaaS, companies can quickly deploy applications and manage workloads without investing in expensive equipment. Major providers of IaaS include Amazon Web Services (AWS), Microsoft Azure, and Google Cloud Platform. This model is particularly beneficial for startups and businesses with fluctuating resource needs.