This page shows how to configure liveness, readiness and startup probes for containers.
The kubelet uses liveness probes to know when to restart a container. For example, liveness probes could catch a deadlock, where an application is running, but unable to make progress. Restarting a container in such a state can help to make the application more available despite bugs.
The kubelet uses readiness probes to know when a container is ready to start accepting traffic.