How does this add node work?

I followed the tutorial to this step, but now I’m confused about how does the add node work. On this case the TexCoord node can still control the density of the material, but if you change the value of Constant2Vector node, it change the position of the map. I’ve seen the introduction of Add node, but still can’t figure it out…Can someone help me with it, thank you a lot~

Simply put the add node adds two number together. in the case of the tex coordinate node and the vector 2, which are both vectors of length two, the add node node outputs a new vector 2 composed of result of add both input vectors components together to put the result in to the new vector 2 respective components. For example Vector A is (0, 3) Vector B is (1, 2) the result of A + B is the vector (1, 5). or (0 + 1, 3 + 2).

Thank you!