Azure AZ-900 - Microsoft Azure Fundamentals

The delivery of computing services—including servers, storage, databases, networking, software, and analytics—over the internet ('the cloud') on a pay-as-you-go pricing model.

A cloud service model where cloud providers host infrastructure components like compute (Virtual Machines), networking, and storage. The customer manages the operating system, middleware, apps, and data.

A cloud service model where the cloud provider manages the underlying OS, runtime, and hardware. Developers only need to manage the application code and data (e.g., Azure App Service, Azure SQL Database).

A cloud service model providing a fully managed, hosted software application over the internet. Users connect via a web browser (e.g., Microsoft 365, Dynamics 365).

A cloud deployment model owned and operated by third-party cloud service providers. Resources are shared across multiple tenants over the public internet.

A cloud deployment model used exclusively by a single business or organization. It can be physically located at an on-premises datacenter or hosted by a third party.

A cloud deployment model combining a private cloud or on-premises infrastructure with a public cloud, allowing data and applications to be shared between them.

Capital Expenditure (CapEx): Upfront spending on physical infrastructure (servers, datacenters) with tax deduction over time.
Operational Expenditure (OpEx): Ongoing spending on services as consumed without upfront costs (pay-as-you-go model).