Cloud infrastructure refers to the hardware and software components — such as servers, storage, a network, and virtualization software — that are needed to support the computing requirements of a cloud computing model.
In cloud computing, these virtualized resources are hosted by a service provider or IT department and are delivered to users over a network or the internet. These resources include virtual machines and components, such as servers, memory, network switches, firewalls, load balancers, and storage.
In a cloud computing architecture, cloud infrastructure refers to the back-end components — the hardware elements found within most enterprise data centers. These include multisocket, multicore servers, persistent storage and local area network equipment, such as switches and routers — but on much greater scale.
Major public cloud providers, such as Amazon Web Services (AWS) or Google Cloud Platform, offer services based on shared, multi-tenant servers. This model requires massive compute capacity to handle both unpredictable changes in user demand and to optimally balance demand across fewer servers. As a result, cloud infrastructure typically consists of high-density systems with shared power.