This is a pay-for-what-you-need-when-you-need-it information technology delivery and service model. In essence, Engine Networks is moving Software-as-a-Service (SaaS) to hardware. With SaaS you pay a monthly fee for Web-based access to a software application. With IaaS you pay a monthly fee for Web-based access to a computing environment that is uniquely configured to your business needs. This might include computing capacity, storage capacity, bandwidth, redundancy, or compliance.