Vagrant Concepts
Internal
Vagrantfile
Box
Vagrant boxes are prepackaged development environments that are the foundation of Vagrant. In most cases, this is usually just a stripped and naked operating system such as Ubuntu, Debian, or CentOS. Boxes exist with the intention to be provisioned with additional features like Apache and PHP using tools like Chef or Puppet. There are publicly available Vagrant boxes: https://www.vagrantup.com/docs/cli/box.html
Dummy Box
Box Operations
Plugin
A plugin extends Vagrant by adding new functionality such as new providers. Plugins extend Vagrant using a stable API. Most of the core Vagrant functionality is implemented using core plugins.
Provider
A provider is the functionality that allows Vagrant to support a specific type of VM. Vagrant ships out of the box with support for VirtualBox, HyperV and Docker. Support for other types of machines can be added via external providers, integrated with Vagrant via plugins. Examples of such providers are AWS provider.