CDNS provide Cloud based services to their clients. Cloud computing, also known as on-demand computing, is a kind of Internet-based computing, where shared resources, data and information are provided 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.Cloud computing and storage solutions provide users and enterprises with various capabilities to store and process their data in third-party data centers. Companies typically utilize cloud-based computing as a way to increase capacity, enhance functionality or add additional services on demand without having to commit to potentially expensive infrastructure costs or increase / train existing in-house support staff.