In general, there isn’t a unique definition for the multiplication of one vector by another, but there are several common “vector products”, such as the dot product and the cross-product.

The dot product of the two vectors (x, y, z) and (a, b, c) is ax + by + cz.

I kinda assumed that in ICE, the Multiply node would give me the same result, but it turns out that Multiply gives (ax, by, cz):