In the Greek language, kubernetes (κυβερνήτης), roughly translated, means "helmsman".
Kubernetes also refers to a technology used to manage containers. In Kubernetes, containers live in pods, which in turn live a node. The collection of nodes, pods, containers, etc gives us the Kubernetes cluster. Invented at Google, kubernates is used to monitor and control such containers. If you have a large number of these containers in your enterprise, the logistics of scaling them up (or down), of monitoring them for errors, or just the mundane task of deploying a latest version of your container(s), can be rather complex. Kubernetes to a large extent automates this.
Kubernetes is not the only choice of tool you have for container orchestration. Docker also ships with a native orchestration tool --Docker Swarm. If you find Kubernetes too complex or expensive, then Swarm is a possible option you may wish to look at.
As Digital Ocean now offers an inexpensive Kubernetes option, this site is now running in a Digital Ocean Kubernetes cluster.