>>13024439It's a convenient shorthand for a combination of a direction with a magnitude.
It *can* be a line segment connecting two positions. But with a fixed direction also.
It *can* have a length.
To describe a flock of starlings at any given moment, you could use a bunch of vectors (an "array") that point from your viewpoint to each starling. Direction in space, and magnitude would be distance in this case.
And have another array, again with one vector for each bird, describing its movement, again pointing in the appropriate direction, in this case whichever way a bird is currently going in space, and magnitude is its current velocity, for example.
Or you could measure a magnetic field, and have a vector pointing the way a compass needle would show, and magnitude could be the strength of the field
Notice how in most cases we have to especially define a starting point for each vector for it to be practically useful. A vector on its own only gives a direction and a magnitude. That's like saying "drive northwest for 10 miles", without taking into account where you are, or where you want to go. Still perfectly valid instructions, but it's up to you to use vectors in a meaningful way.
