Cloud computing is a model for delivering information technology services in which resources are retrieved from the internet through web-based tools and applications rather than a direct connection to a server. Data and software packages are stored in servers; However, a cloud computing structure allows access to information as long as an electronic device has access to the web. In a simple term, instead of storing information in a hardware, we store the information over the internet. Cloud benefits a business as this type of system allows employees to work remotely.
Companies may find that cloud computing allows them to reduce the cost of information management since they are not required to own their own servers and can use capacity leased from third parties. Breaking down the cloud computing, here are four deployment models,
The cloud infrastructure is provisioned for exclusive use by a single organization comprising multiple consumers (e.g., business units). It may be owned, managed, and operated by the organization, a third party, or some combination of them, and it may exist on or off premises.
The cloud infrastructure is provisioned for exclusive use by a specific community of consumers from organizations that have shared concerns (e.g., mission, security requirements, policy, and compliance considerations). It may be owned, managed, and operated by one or more of the organizations in the community, a third party, or some combination of them, and it may exist on or off premises.
The cloud infrastructure is provisioned for open use by the general public. It may be owned, managed, and operated by a business, academic, or government organization, or some combination of them. It exists on the premises of the cloud provider.
The cloud infrastructure is a composition of two or more distinct cloud infrastructures (private, community, or public) that remain unique entities, but are bound together by standardized or proprietary technology that enables data and application portability (e.g., cloud bursting for load balancing between clouds
Source: Investopedia and Service Architecture