公用云（Public cloud） 是第三方提供一般公众或大型产业集体使用的云端基础设施，拥有它的组织出售云端服务，系统服务提供者借由租借方式提供客户有能力部署及使用云端服务 。

• 私有云（Private cloud）
• 社区云（Community cloud）
• 混合云（Hybrid cloud）

Cloud computing, also on-demand computing, is a kind of Internet-based computing that provides shared processing resources and data to computers and other devices on demand. It is a model for enabling ubiquitous, on-demand access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications and services), which can be rapidly provisioned and released with minimal management effort. Cloud computing and storage solutions provide users and enterprises with various capabilities to store and process their data in third-party data centers. It relies on sharing of resources to achieve coherence and economy of scale, similar to a utility (like the electricity grid) over a network.