Cloud computing is a technology that many businesses are considering for financial and practical reasons. Deciding to use cloud computing, however, is just the first of many decisions you will have to make. Do you want to use public, private, or hybrid clouds? Do you want platform as a service, software as a service, or infrastructure as a service? And ultimately, you will need to decide if you want managed or unmanaged cloud hosting.
Cloud computing in general provides users with a packaged set of tools that make it easier to setup and deploy servers and services. Once deployed, the service provider may continue to monitor, regulate, and support all software activity, or it may cut you loose and allow you to freely use the services as you see fit, without providing support for any software you use. The former is called managed cloud hosting, while the latter is called unmanaged cloud hosting.
Managed cloud hosting is usually a more long-term arrangement, and the user normally subscribes to some form of hybrid cloud deployment. The service provider offers availability and redundancy for mission-critical applications without the vendor lock-in often associated with IT outsourcing.
Unmanaged cloud hosting still provides the same core services you have come to expect from cloud computing, but you also get unrestricted access to your server and any installation of software or other tools you need. What you will not get is support for the customizations and third-party software that you install. The OS and any default configuration will be supported, but anything you add is your own responsibility.
Both of these cloud options have their advantages, and the decision to choose one over the other greatly depends on how you want to use the services and how much flexibility vs. support you need from the provider.