To predict the instantaneous position s (t) of a body at any time instant t, we need to know
1) the time instant t
2) s(0) its initial position at t = 0: s(0)
3) v(t) the instantaneous speed v at every instant of the object.
4) the direction of velocity at every instant of the object:
(3) and (4) combined is the instantaneous velocity vector.