Information technology before the cloud operated on-premises data centers, where the company takes care of every single aspect of the hardware, infrastructure, security, and maintenance operations. The company was responsible for procuring the hardware servers, installing and configuring them, and executing regular maintenance for upgrade and batching, in addition to safeguarding the information in the company data center. With cloud technology, companies can reduce a lot of expenses, time, and effort, where the vendor provides all required hardware, infrastructure, security and maintenance operations against subscriptions. Microsoft Cloud over Microsoft Azure technologies offers three different models and these will depend on the customer needs. The first option is Software as a Service (SaaS), the second is Platform as a Service (PaaS), and the third is Infrastructure as a Service (IaaS). The following diagram illustrates the difference between each offering along with the traditional on-premises offering:

If we look at the previous diagram from left to right, with the on-premises option the customer manages everything from the application to the lowest networking aspects. Moving to IaaS, the customer here manages the application, database and operating system, but the vendor will take care of the core infrastructure work storage, networking, and servers. In PaaS, the scope of the customer narrows to merely being responsible for the application, and runtime, with the rest of the stack being managed by the vendor. SaaS is the final offering where the vendor manages the whole stack of the application, and the customer is only consuming application usage. Microsoft Dynamics 365 for Finance and Operations is available on the SaaS model, and on-premises.