Vagrant lets us create lightweight and portable dev envs, while Puppet makes configuring them easy. The presentation is about how this great tandem can make PHP developers life easier.
Video of the talk (in Polish): https://www.youtube.com/watch?v=CFs6BFfYTCs
Further reading:
http://www.vagrantup.com/
https://puppetlabs.com/puppet/what-is-puppet/
https://puphpet.com/
http://net.tutsplus.com/tutorials/php/vagrant-what-why-and-how/