The software responsible for running the containers, is called (elementary my dear Watson) the container runtime.
Common container runtimes include containerd, CRI-O, Docker Engine, and the Mirantis Container Runtime.
Stuff you wanna know:
- You need to install a container runtime into each node in the cluster so that Pods can run there.
- Kubernetes releases before v1.24 included a direct integration with Docker Engine, using a component named dockershim. Kubernetes 1.24 requires that you use a runtime that conforms with the Container Runtime Interface (CRI).