Kubectl is the command-line tool used to interact with the Kubernetes API server, allowing you to manage Kubernetes resources.
Kubectl is the platform using which you can pass commands to the cluster.
So, it basically provides the CLI to run commands against the Kubernetes cluster with various ways to create and manage the Kubernetes component.
https://blog.getambassador.io/getting-edgy-what-is-kubectl-ed11ead54555