[Math] the term for vector in same direction but with different length

Question

I'll say $\vec{a}$ and $\vec{b}$ are collinear if they lies in same line, like (1, 2, 3) and (-1, -2, -3).
What should I call two vectors in same direction but with different lengths? like (1, 2, 3) and (2, 4, 6). (Of course they are collinear, but is there any more specific term for them?)

Answer 1

You can say (1,2,3) and (2,4,6) are parallel.

As $ \vec{a} = k \vec{b}$

Edit - Difference between parallel and collinear

If two parallel vectors have angle = 0 between them that is both are in same direction but collinear vector lie in same plane they may be parallel or anti parallel that is angle = 180.