Role and traits are the same thing.

For some definition of "traits" that is. To clarify, Traits were the original idea developed by the Smalltalk people and which I implemented in Class::Trait. In Moose however we use trait differently, it has come to mean "role applied to an instance" and sometime specifically to a meta-level instance.

Roles weren't introduced by Moose

Exactly they were one of the many features we borrowed from Perl 6 :)