For the most part if your application is developed 12 factor style: http://12factor.net, you shouldn't have to worry about these things as a developer. Stuff like this is more in the ops space.

Cloud orchestration: the logic for how your platform provisions and launches instances (think ec2) into your fleet of resources.

Container orchestration: the logic for how your applications (containers) are distributed across your fleet of instances

Kubernetes: Software that runs on your fleet and manages how/where/when container orchestration happens. There are many players in this space such as mesosphere, swarm, ecs and so on.