This node that allows you to split a vector/colour into the three components or merge them together.
You can also selectively overwrite a single component.
The XYZ inputs have precedence over the Vector inputs.
The Length output provides the length of the vector, the Normalised output a normalised version of the vector.
Set # / # / # to
These controls allow you to swizzle components of a vector - basically swap them around any way you'd like to.