Vagrant allows developers to run identical development environments by configuring and provisioning virtual machines. It helps match the development and production environments. To use Vagrant, install VirtualBox, Vagrant, and a base box image. The Vagrantfile configures settings like the hostname, IP, shared folders, and provisioning steps. Common commands include vagrant up to run the virtual machine, vagrant halt to shut it down, and vagrant destroy to remove it. Vagrant can also package custom virtual machine images to share.