OpenStack and KVM are two different concepts and belong to two open source technologies widely used in the field of cloud computing, but they have different positioning and functions. There are some differences between them. The meaning and difference between the two are detailed below!

　　OpenStack

　　OpenStack is an open source cloud computing platform that provides a set of tools and components for building and managing cloud infrastructure. The goal of OpenStack is to realize automated deployment, elastic scaling and resource management of public and private clouds. It contains multiple modules, such as computing (Nova), network (Neutron), storage (Cinder, Swift) and identity authentication (Keystone), etc., which can be used to create and manage virtual machines, network and storage resources.

　　KVM

　　KVM (Kernel-based Virtual Machine) is an open source virtualization technology, which is a virtualization solution based on the Linux kernel. KVM allows the creation and management of multiple virtual machines on the host machine and provides direct access to hardware to achieve high-performance virtualization.

　　The difference is as follows:

　　OpenStack is a complete cloud computing platform that provides a rich set of tools and components to build and manage cloud infrastructure. KVM is just an implementation of virtualization technology.

　　OpenStack can run on a variety of virtualization platforms, including KVM, VMware, Hyper-V, etc. KVM is a specific virtualization technology, which is a virtualization solution based on the Linux kernel.

　　OpenStack provides more advanced functions and management tools, such as automated deployment, resource scheduling, elastic scaling, etc., and is suitable for building and managing complex cloud infrastructure. KVM mainly focuses on providing a high-performance virtualization environment.

　　OpenStack can be used in conjunction with a variety of virtualization technologies, including KVM, VMware, Hyper-V, etc. You can choose a suitable virtualization platform according to your needs.

　　In general, OpenStack is a larger cloud computing platform, and KVM is one of the technologies that implements virtualization. Using OpenStack allows you to build and manage cloud infrastructure more comprehensively, while KVM mainly focuses on providing a high-performance virtualization environment. As two common cloud computing open source technologies, each has its own unique advantages and disadvantages. Therefore, when renting a cloud server, how to choose a cloud computing platform still needs to be based on the actual usage of the cloud server provider.