Puppet inheritance VS puppet composition.?

What are the differnces between Puppet inheritance VS Puppet composition.?

I just came cross puppet inheritance lately. A few questions around it:

1.Is it a good practice to use puppet inheritance.? I've been told by some of the experienced puppet colleagues Inheritance in puppet is not very good, I was not quite convinced.

2.Coming from OO world, I really want to understand under the cover, how puppet inheritance works, how overriding works as well.