Information technology (IT) infrastructure supplies the equipment, software, connections, and services that support an organization's information processing. IT architecture describes how these components fit together, including dependencies between end-user devices, network infrastructure, and servers.
A virtualized server separates physical resources from the computing environments using them. Operating systems and applications still require administration when their servers exist as software-defined environments.
The architecture contains distinct layers.
- Physical hardware: Tangible equipment supplies processing, memory, storage, and connections. A rack-mounted computer provides processing capacity; a storage device retains files after processing ends.
- Hypervisor: Virtualization software allocates physical resources among separate virtual machines and supports their isolation. Its administrative settings affect the environments sharing that physical host.
- Virtual machine: A software-defined computer receives virtual processing, memory, storage, and network resources. Multiple virtual machines can run different operating systems on one physical server.
- Operating system: System software manages hardware resources, files, processes, and system access while providing services that applications use. Windows Server and Linux are recognizable examples.
Common mistakes
- Server treated as hardware only. A server role may operate on a virtual machine or share a physical machine with other roles.
- Network functions merged. A switch connects local devices, a router connects networks, and a load balancer distributes requests among servers.
- Browser access determines the model. A browser can administer IaaS, deploy to PaaS, or use SaaS; the supplied capability determines classification.
Bottom line
- IT architecture connects physical hardware, virtualization, operating systems, applications, data, networks, and end-user devices.
- Network components have distinct connection, routing, filtering, remote-access, and workload-distribution purposes.
- IaaS supplies infrastructure, PaaS supplies a managed application environment, and SaaS supplies a finished application.
- Public, private, and hybrid deployment describe availability and arrangement of cloud infrastructure independently of service models.
Exam shortcut
Identify the requested dimension first: component purpose, supplied capability, deployment arrangement, operational responsibility, or governance purpose. For service-model choices, locate the highest layer the provider maintains. Look for customer-managed operating systems, customer-deployed code, or a finished hosted application. For deployment choices, inspect the access population and connections. A provider-owned building does not settle whether the cloud is public or private.
The full lesson (about 4,099 words, 27 min read) adds 2 worked examples, all 6 common mistakes, a self-check, free in the app.
Learning objectives
- I.A1
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