Question

is the displacement of an object during a specific unit of time.

Answer 1

That's the definition of average velocity (a vector). Average velocity = displacement ÷ time interval, v_avg = Δx / Δt. If you drop direction (use distance instead of displacement) you get average speed (a scalar). Instantaneous velocity is the limit as Δt → 0: v = dx/dt. Common SI unit: m/s.

Example: 100 m east in 20 s → v_avg = 100 m / 20 s = 5 m/s east.