[Andres]

Originally Posted by Sergeantmajor

well, im positive a PMC and a mercenary isnt the same thing.

Originally Posted by Wikipedia

PMC:
private military company (PMC) provides specialised expertise or services of a military nature, sometimes called or classified as mercenary ("soldiers for hire").[1]


Mercenary:
"A mercenary is a person who takes part in an armed conflict who is not a national of a Party to the conflict and "is motivated to take part in the hostilities essentially by the desire for private gain and, in fact, is promised, by or on behalf of a Party to the conflict, material compensation substantially in excess of that promised or paid to combatants of similar ranks and functions in the armed forces of that Party".

The differences I can draw from the two is how you perceive their involvement in whatever they've been hired to do.