Cloud Computing Overview - MSDN Documentation

What is Cloud Computing?

Cloud computing is the delivery of computing services—including servers, storage, databases, networking, software, analytics, and intelligence—over the Internet (“the cloud”) to offer faster innovation, flexible resources, and economies of scale. You typically pay only for cloud services you use, helping lower your operating costs, run your infrastructure more efficiently, and scale as your business needs change.

It's a model for enabling ubiquitous, convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications, and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction.

Key Characteristics

On-demand self-service: A consumer can unilaterally provision computing capabilities, such as server time and network storage, as needed automatically without requiring human interaction with each service’s provider.
Broad network access: Capabilities are available over the network and accessed through standard mechanisms that promote use by heterogeneous thin or thick client platforms (e.g., mobile phones, tablets, laptops, and workstations).
Resource pooling: The provider’s computing resources are pooled to serve multiple consumers using a multi-tenant model, with different physical and virtual resources dynamically assigned and reassigned according to consumer demand.
Rapid elasticity: Capabilities can be elastically provisioned and released, in some cases automatically, to scale rapidly outward and inward commensurate with demand. To the consumer, the capabilities available for provisioning often appear to be unlimited and can be appropriated in any quantity at any time.
Measured service: Cloud systems automatically control and optimize resource use by leveraging a metering capability at some level of abstraction appropriate to the type of service (e.g., storage, processing, bandwidth, and active user accounts). Resource usage can be monitored, controlled, and reported, providing transparency for both the provider and consumer of the utilized service.

The Three Cloud Service Models

Cloud computing offers different types of services, often categorized into three main models:

Infrastructure as a Service (IaaS): Provides access to fundamental computing resources like virtual machines, storage, and networks. You manage the operating system, middleware, and applications.
Example: Azure Virtual Machines.
Platform as a Service (PaaS): Provides a platform for developing, running, and managing applications without the complexity of building and maintaining the infrastructure typically associated with it.
Example: Azure App Service.
Software as a Service (SaaS): Provides ready-to-use applications over the Internet, typically on a subscription basis. The provider manages everything.
Example: Microsoft 365.

Deployment Models

Cloud computing can be deployed in several ways:

Public Cloud: Resources are owned and operated by a third-party cloud service provider and delivered over the Internet.
Private Cloud: Cloud infrastructure is operated solely for an organization. It can be managed internally or by a third party and hosted either internally or externally.
Hybrid Cloud: Combines public and private clouds, bound together by technology that allows data and applications to be shared between them.

Benefits of Cloud Computing

Cost savings and reduced capital expenditure
Scalability and elasticity
Global reach and accessibility
Improved collaboration and productivity
Enhanced security and disaster recovery
Faster innovation and deployment

Getting Started

Explore the different cloud service models and deployment options to find the best fit for your needs. Microsoft Azure offers a comprehensive suite of cloud services to help you build, deploy, and manage applications and services through a global network of data centers.