The term is also sometimes used for people who advise their friends to be selfish and morally incorrect, The devils advocate does not do bad stuff, but he advises others to do so. Often humorously, so he cannot even be blamed. Or he might point out why an immoral/unfair way to act would be more profitable.
For example, if my friend comes to me asking advice about how to motivate her employees and I tell her to fire all the unhappy people, I am playing the devils advocate.
Playing Devil's Advocate is when you take a stance that you or a group of people you are with don't usually agree with and support it and usually just disagree a lot as well.
It's really useful when it comes to making debates more lively since it provides dissent although the name does have some unusual connotations that may make disagreeing with the stance genuinely a little weird.
Hope that's clear for you :)
Thanks that clears up so much. I hear it all the time and now I can finally say it myself and look like a knowledgeable boss. :D Thank you!
You are welcome ^_^