KubeOne versions are expressed as x.y.z, where x is the major version, y is the minor version, and z is the patch version.
KubeOne follows the Kubernetes release model and cycle, though for practical reasons releases are a bit delayed to ensure compatibility with Kubernetes. In general, the latest two minor versions of KubeOne are supported, n and n-1, i.e. the current 1.8 and 1.7. With the release of a new minor KubeOne version, support for the oldest supported KubeOne version is dropped.