Cloud computing
Cloud computing is 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. This cloud model is composed of five essential characteristics, three service models, and four deployment models.
Essential Characteristics:
On-demand self-service:
Users can provision computing resources such as server time and network storage as needed automatically, without requiring human interaction with each service provider.
Broad network access:
Services are available over the network and accessed through standard mechanisms that promote use by heterogeneous thin or thick client platforms.
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.
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.
Service Models:
Infrastructure as a Service (IaaS):
Provides virtualized computing resources over the internet. Users can rent IT infrastructure (e.g., servers, virtual machines, storage, and networking) on a pay-as-you-go basis.
Platform as a Service (PaaS):
Provides a platform allowing customers to develop, run, and manage applications without the complexity of building and maintaining the underlying infrastructure. Developers can focus solely on their applications.
Software as a Service (SaaS):
Delivers software applications over the internet on a subscription basis. Users access the application via a web browser without needing to install or maintain any software.
Deployment Models:
Public Cloud:
Services are delivered over the public internet and available to anyone who wants to purchase them. They may be free or offered on a pay-per-usage model.
Private Cloud:
Cloud infrastructure is operated solely for a single organization. It may be managed by the organization itself or by a third party and can be physically located on-premises or off-premises.
Hybrid Cloud:
Combines public and private clouds, allowing data and applications to be shared between them. This model provides greater flexibility and optimization of existing infrastructure while still maintaining some level of control over sensitive data.
Community Cloud:
Infrastructure is shared by several organizations with similar interests, concerns, or compliance requirements. It may be managed by the organizations or a third party and can be hosted on-premises or off-premises.
Understanding these concepts is essential for businesses and individuals looking to leverage cloud computing for their IT needs.