Infrastructure as a Service (IaaS) is the most basic category of cloud computing services. With Infrastructure as a Service (IaaS), you rent IT infrastructure servers and virtual machines (VMs), storage, networks, and operating systems from a cloud provider on a pay-as-you-go basis. It's an instant computing infrastructure, provisioned and managed over the internet.
Infrastructure as a Service (IaaS) Characteristics
Upfront Costs - Infrastructure as a Service (IaaS) has no upfront costs. Users pay only for what they consume.
User Ownership - The user is responsible for the purchase, installation, configuration, and management of their own software operating systems, middle ware, and applications.
Cloud Provider Ownership - The cloud provider is responsible for ensuring that the underlying cloud infrastructure (such as virtual machines, storage and networking) is available for the user.
Disadvantages of Infrastructure as a Service (IaaS)
Management - The shared responsibility model applies; the user manages and maintains the services they have provisioned, and the cloud provider manages and maintains the cloud infrastructure.
Common usage of Infrastructure as a Service (IaaS)
Migrating Workloads - Typically, Infrastructure as a Service (IaaS) facilities are managed in a similar way as on-premises infrastructure and provide an easy migration path for moving existing applications to the cloud.
Test and Development - Teams can quickly set up and dismantle test and development environments, bringing new applications to market faster. Infrastructure as a Service (IaaS) makes scaling development testing environments up and down fast and economical.
Website Hosting - Running websites using Infrastructure as a Service (IaaS) can be less expensive than traditional web hosting.
Storage, Backup, and Recovery - Organizations avoid the capital outlay and complexity of storage management, which typically requires a skilled staff to manage data and meet legal and compliance requirements. Infrastructure as a Service (IaaS) is useful for managing unpredictable demand and steadily growing storage needs. It can also simplify the planning and management of backup and recovery systems.
When using Infrastructure as a Service (IaaS), ensuring that a service is up and running is a shared responsibility: the cloud provider is responsible for ensuring the cloud infrastructure is functioning correctly; the cloud customer is responsible for ensuring the service they are using is configured correctly, is up to date, and is available to their customers.