Final answer:
The horizontal wooden/metal bar in the studio which the dancer holds onto for support is called Barre.
Step-by-step explanation:
The term for the horizontal wooden/metal bar in the studio which the dancer holds onto for support is Barre. The barre is an essential tool in ballet training and is used to help dancers improve their balance, alignment, and technique. It provides support and stability for the dancers while they perform various exercises and stretches.