Kubernetes is an open-source container system for automating computer application deployment, scaling and management. It has a specific server architecture and an elaborate group of software built around it for the server.
One article describes Kubernetes as a "workload distribution and orchestration mechanism for clustered servers in a data center." Another article elaborates on this definition, focusing on a common analogy that illustrates Kubernetes as an orchestra conductor coordinating different instruments and sections. Kubernetes organizes the sections that make up a computer application sitting on a server. It responds to many users quickly and efficiently, even though there is demand at all times for other parts of the application. Some people consider it to be a "super coordinator."
Kubernetes also improves server structures. It serves the computer applications we use today — from the emails you get on your laptop to the videos you stream through your phone — and creates more efficiency. Using the orchestra analogy, consider the owner of a concert hall who separates the space into multiple smaller venues so that several orchestras can play simultaneously. While the site is being used more efficiently, it isn’t an ideal situation quite yet, as you would need multiple conductors and orchestras to have all of these concerts in the same venue. This isn't efficient.
Instead, picture a virtual reality (VR) technology — using holograms, perhaps, rather than VR goggles — that allows an audience to go to one of these concerts whenever they want and experience a virtual performance equivalent to the real thing.
Similar to the VR technology in the orchestra analogy, Kubernetes delivers the image of an application to users in real time, on demand. It temporarily uses whatever server space is available for the task. Then, when the application is no longer needed, Kubernetes shuts down and withdraws it from that server space, which frees up the space to be used in other ways.