What is that “firm/pointy” sensitive spot inside the vagina?

So my girlfriend and I have been exploring things slowly, and I’ve noticed something I’m curious about from an anatomy perspective.

When I stimulate inside her vagina, she says most of the deeper areas don’t feel very sensitive. But there’s a specific spot along the upper/front wall (not too deep) that feels very different. It feels a bit firmer or slightly raised compared to the surrounding area, almost like a pointy fleshy appendage, and when that area is rubbed or hit up with pressure, she feels it much more intensely.

I’m trying to understand what that actually is. Is that what people refer to as the G-spot, or is it related to the internal structure of the clitoris or just a concentration of nerve endings?