Position vector- The position of an object refers to its location in space at a certain moment of time.It is measured as a vector whose tail is at the origin and head is at the object.

This vector is known as position vector.

Displacement vector- It is measured as a vector joining the initial position of the object to its final position.So, basically displacement vector is change in two position vectors.

In the given the figure, initial Position of the object is P₁  and r₁ is the position vector.

P₂ is the final position of the object and r₂ is the position vector.

And Displacement vector is Δr =r₂-r₁