"collinear parallel" vs "collinear" I'm trying to understand the difference between "collinear parallel" and "collinear" when describing vectors. "Collinear parallel" seems mean that the vectors are "on the same line" and that the angle between them is zero; so they are in the same direction. Is that the correct way to interpret the phrase? Then, "collinear" used by itself just means that they're in the same line, but we can't make an assumption about their direction being the same or opposite? Thanks.