Kubectl contexts allow users to work with multiple Kubernetes clusters using one kubectl installation. Contexts are stored in the kubeconfig file, which contains cluster URLs, user credentials, and default namespaces for each context. The kubectl config commands can be used to manage these contexts, including getting the current context, listing all available contexts, setting a specific context, adding new contexts, deleting contexts, and displaying the contents of the kubeconfig file. Overriding context settings is also possible using regular Kubectl flags. Spacelift can be used for managing Kubernetes projects with features like GitOps flow, custom policies, plan policies, approval policies, and more.