Novice question when looking at a 2013 Ford Mustang Convertible V6

I was looking at a used 2013 Mustang on a car lot. As I was looking over the car I saw some oily, greasy, residue, seeping coming out of this area of the engine. (Circled with arrow pointing in photo below)
Can someone tell me what part that is and why I might see seepage? Sorry, I am a novice and was looking for some info. Thanks in advance.