Cloud computing is the use of various computing services, such as software, platforms, servers, and storage, that are delivered over the internet. It utilizes a global network of servers with unique functions that collectively form "the cloud". Common cloud service models include infrastructure as a service (IaaS), platform as a service (PaaS), and software as a service (SaaS). The document discusses cloud computing concepts such as layers, architecture, types, characteristics, security concerns, uses, and provides a conclusion.