Four O'clock Foto- Potato Salad

I take leftover baked potatoes and let them cool. Then I add cute up celery, onion, boiled eggs. The mixture, juice, dressing or whatever YOU call it is made of apple cider vinegar, Hellman's and mustard. I also salt and pepper the crap out of it..

Baked Potatoes
Onion
Celery
Boiled Eggs

Apple Cider Vinegar
Hellman's
Mustard

Salt and Pepper..

What do you call the sauce on potato salad?