While it's common for individuals or businesses to purchase computer hardware and then periodically replace or upgrade it, they can also lease physical and virtual hardware from a service provider. The provider then becomes responsible for keeping hardware up to date, including its various physical components and the software running on it. This is known as the HaaS model.
The biggest advantage of HaaS is that it reduces the costs of hardware purchases and maintenance, enabling organizations to shift from a capital expense budget to a generally less expensive operating expense budget. Also, since most HaaS offerings are based on a pay-as-you-go model, it makes it easier for organizations to control costs, while still having access to the hardware they need for their operational and business continuity.