Git is a free and open source distributed code management and version control system that is distributed under the GNU General Public License version 2.
GitHub is a web-based revision control hosting service for software development and code sharing. GitHub was started in 2008 and was founded on Git, an open source code management system built created by Linus Torvalds to make software builds faster.
Google Container Engine is a management and orchestration system for Docker containers and container clusters that run within Google's public cloud services. Google Container Engine is based on Kubernetes, Google's open source container management system.