The cloud service that uses a pay-as-you-go model for computing resources is typically categorized as Infrastructure as a Service (IaaS). IaaS enables users to rent computing resources, such as servers, storage, and networking, from cloud providers on a flexible basis. Users are billed based on their actual usage, allowing scalability and cost efficiency. This model is beneficial for businesses with fluctuating workloads, as it eliminates the need for significant upfront investments in hardware.