Vagrant can create and automate operating system environments on virtual machines using simple yaml configuration scripts.
These Virtual Machine (VM) are provisioned on top of VirtualBox, VMWare, AWS, and many other virtual machine providers. Using industry standard tooling such as bash scripts, Chef or Puppet you can automatically install and configure software on the VM.
Vagrant provides consistent environments such that code works regardless of what kind of computers team members use for their development, or creative, workflow. Furthermore it claims a level of production parity that can be achieved, but this would be highly dependent on the workflow of development teams.