Using new operator without naming instance

So what is the difference between

Vector3 osman = new Vector3(15, 30, 45);


transform.Rotate(new Vector3(15,30,45)*Time.deltaTime); ?? Performance issues? in functionality, they both work, but is there an advantage to using one of them?

I see no performance benefit in using one or the other, they are pretty much the same. If you’re going to use the vector again later on, then assign it to a variable, otherwise use the second method would be my recommendation.