Question

what is a vector? try to answer with higher physics.

Answer 1

Vectors are quantities which have both magnitude and direction. It is a geometric entity. Examples are displacement, momentum and the like.

Answer 2

Vector is something we can't see but we can feel its effect
In maths it is just something that has magnitude and direction
But in physics we have its examples
a force acts on object we can't see that force 
but we can see from where it exerted and on which it is exerted
similarly we see an object moving with velocity we define it as vector
So vector is actually or imagination which bring on consequences of action we observe
that's why we use mostly relatistive vectors