It groups containers that make up an application into logical units for easy management and discovery. Kubernetes builds upon 15 years of experience of running production workloads at Google, combined with best-of-breed ideas and practices from the community.
Kubernetes is an open source project that enables software teams of all sizes, from a small startup to a Fortune 100 company, to automate deploying, scaling, and managing applications on a group or cluster of server machines. These applications can include everything from internal-facing web applications like a content management system to marquee web properties like Gmail to big data processing.
Thomas Nys made a nice presentation explaining the technology and includes interesting links for further reading and exploration.