roles and profiles can basically be thought of a a egyptian pyramid structure.
The pyramid is broken into 3 levels
– top tier = roles
– middle = profiles
– bottom tier = puppet modules and puppet module libraries.
The goal is to only assign one (role) class per vm.
http://puppetlabs.com/presentations/designing-puppet-rolesprofiles-pattern
https://puppetlabs.com/presentations/designing-puppet-rolesprofiles-pattern
http://puppetlabs.com/blog/best-practices-building-puppet-modules
http://puppetlunch.com/puppet/roles-and-profiles.html