Cloud Application — The “top” layer of the Cloud Pyramid where “applications” are run and interacted with via a web-browser. Cloud Applications are tightly controlled, leaving little room for modification.

Cloud Center — A datacenter in the “cloud” utilizing standards-based datacenter-like infrastructure.

Cloud Computing — A computing capability that provides an abstraction between the computing resource and its underlying technical architecture (e.g., servers, storage, networks), enabling convenient, on-demand network access to a shared pool of configurable computing resources that can be rapidly provisioned and released with minimal management effort or service provider interaction.” This definition states that clouds have five essential characteristics: on-demand self-service, broad network access, resource pooling, rapid elasticity, and measured service. Narrowly speaking, cloud computing is client-server computing that abstract the details of the server away—one requests a service (resource), not a specific server (machine).

Cloud Hosting — A type of internet hosting where the client leases virtualized, dynamically scalable infrastructure on an as-needed basis. Users frequently have the choice of operating system and other infrastructure components. Typically cloud hosting is self-service, billed hourly or monthly, and controlled via a web interface or API.

Cloud Infrastructure — The “bottom” layer of the Cloud Pyramid is the delivery of computer infrastructure through paravirtualization. This includes servers, networks and other hardware appliances delivered as either Infrastructure Web Services or “cloudcenters”. Full control of the infrastructure is provided at this level.

Cloud Platform — The “middle” layer of the Cloud Pyramid which provides a computing platform or framework (e.g., .NET, Ruby on Rails, or Python) as a service or stack. Control is limited to that of the platform or framework, but not at a lower level (server infrastructure). Examples include: Google AppEngine or Microsoft Azure.

Cloud Providers — Providers whose product/platform is based on virtualization of computing resources and a utiliy-based payment model.

Cloud Servers — Virtualized servers running Windows or Linux operating systems that are instantiated via a web interface or API. Cloud Servers behave in the same manner as physical ones and can be controlled at an administrator or root level, depending on the server type and Cloud Hosting provider.

Cloud Pyramid — A visual representation of Cloud Computing layers where differing segments are broken out by functionality. Simplified version includes: Infrastructure, Platform and Application layers.

Cloud Hosting (often also referred to as clustered hosting) is a step up from the shared hosting infrastructure that is commonly used today. By handling security, load balancing and server resources virtually you are no longer restricted to the limits of one physical piece of hardware. In basic terms, online operations are not limited to a single server, they have access to the processing power of a number of servers that are distributed in real time.

In a physical environment, a web site (for instance) is limited to the resource constraints that is housed within the physical unit (RAM, processing power, bandwidth etc). The concept of a cloud infrastructure no longer has this limitation – you, as a customer, can purchase as much computing power as you need from a virtually inexhaustible. The nature of the infrastructure means that scaling up and down is seemless and thus spikes in traffic aren’t problematic.

Load-balancing occurs at the software level and is dynamically load-balanced across a number of servers. Servers can be added or removed from the cluster with no impact or downtime on hosted applications meaning less disruption for customers. The cloud architecture has the ability to provide small and medium enterprises the stability and resilience of a web hosting architecture that a few years ago only huge corporate organizations could obtain through huge IT expenditure.

Salman @ VPSGuys