Funnel cloud do not become tornadoes. Also, a tornado does not necessarily need to have an associated condensation funnel. If strong cyclonic winds are occurring at the surface (and connected to a cloud base, regardless of condensation), then the feature is a tornado. Some tornadoes may appear only as a debris swirl, with no obvious funnel cloud extending below the rotating cloud base. In cloud nomenclature, any funnel- or inverted-funnel-shaped cloud descending from cumulus or cumulonimbus clouds is technically described as an accessory feature called "tuba". The terms "tuba" and "funnel cloud" are nearly but not exactly synonymous; a wall cloud, for
Cloud computing issues Three types of vendor lock-in can occur with cloud computing: Heterogeneous cloud computing is described as a type of cloud environment that prevents vendor lock-in, and aligns with enterprise data centers that are operating hybrid cloud models. The absence of vendor lock-in lets cloud administrators select his or her choice of hypervisors for specific tasks, or to deploy virtualized infrastructures to other enterprises without the need to consider the flavor of hypervisor in the other enterprise. A heterogeneous cloud is considered one that includes on-premises private clouds, public clouds and software-as-a-service clouds. Heterogeneous clouds can work with environments that are