Infrastructure as a service (IaaS) is a cloud computing model that offers remote computer, storage, and networking resources that are available on demand. These services are typically offered on a pay-as-you-go basis. The user is given control of virtual machines (software running on a cloud server that acts as its own independent computer). These virtual machines are managed by another peice of software running on the cloud server, known as a hypervisor. Examples of this type of software include Oracle VirtualBox or VMware ESXi. The user is allowed to run arbitrary software on these virtual machines, including operating systems.
IaaS provides an API to control the low-level details of the underlying network infrastructure (e.g., backups, partitioning, security, and physical resources). While they do not have direct access to the infrastructure, users can configure:
- Operating systems
- Deployed applications
- Networking components (e.g., host firewalls)
The user’s responsibilities include the following:
- Maintaining the virtual machines.
- This includes keeping operating systems and applications patched and up-to-date.
- Paying the cloud service only for the number of resources allocated and consumed.