Cloud Computing Definitions

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. (source NIST)

Cloud Computing Roles

• Cloud Service Customer - The person or company purchasing cloud services from a cloud service provider.
• Cloud Service Provider - Company or entity offering cloud services.
• Cloud Service Partner - Third-party offering cloud-based services using a CSP.
• Cloud Service Broker - Provides cloud services to customers using one or multiple CSPs.

Key Cloud Computing 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 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).
• Multi-tenancy - Multiple customers and applications that are running withing the same environment and share the same resources but are isolated from one another.
• Rapid elasticity and scalability - 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.
• 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. There is a sense of location independence in that the customer generally has no control or knowledge over the exact location of the provided resources but may be able to specify location at a higher level of abstraction (e.g., country, state, or datacenter). Examples of resources include storage, processing, memory, and network bandwidth.
• 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.

Building Block Technology

• Virtualization - The sharing of resources among a large number of services and customers. There are two types: type 1 and type 2. Type 1 is a hypervisor, it is a specifically made OS for virtualization and is more secure. Type 2 is VM software made to run in another OS (like VMware and Virtualbox), it is generally less secure.
• Storage - There are two main types of storage for cloud computing: storage area networks (SANs) and network-attached storage (NAS). A SAN provides storage to multiple resources within a specific domain. A NAS uses TCP/IP to provide file-level access. The CSP is responsible for the security of the storage resources
• Networking - The internet is a large network of networks that allow cloud computing. All resources in the cloud are access through the internet.
• Databases - Databases organize and allow for quick retrieval of customer data.
• Orchestration - Manages the many resources that is used for the cloud through automation of tasks.