User Portlet User Portlet

Hello everybody, Does anybody know the meaning of the operator & /@ used in expressions like: names = StringSplit[#, {".csv", "/"}][[-1]] & /@ filenames; where filenames is a list of filenames in a path.   I would like also to know...
I just find a solution. The command Position can do that. For further information It is so easy! I love mathematica!
Already restarted and the problem is still there. Thank you very much for all these informations, I will try to contact them. bye