Is VVS a real diamond?

I'm curious, could you clarify for me if VVS is truly a diamond? I've heard it mentioned in the context of jewelry and gemstones, but I'm not entirely sure if it's a legitimate diamond grading or just a term used loosely. Could you elaborate on what VVS stands for and whether it indeed signifies a diamond's quality and authenticity? I'd appreciate any insights you can provide to help me better understand this terminology.