The Virtual Desktop Infrastructure (VDI) in the cloud is typically delivered as a part of Desktop as a Service (DaaS). This cloud service model provides hosted virtual desktops which the law firm can access over the internet, minimizing the need for on-premises hardware and maintenance. SaaS would not be suitable because it generally refers to software applications delivered over the web rather than full desktop environments. IaaS would require the firm's IT staff to manage the virtual machines and operating systems. PaaS provides an environment for development and deployment of applications, which is not the primary requirement of the law firm.