Displacement

Definition: Displacement

The displacement of a point mass during the time interval $\Delta t$ between two moments $t_1$ and $t_2>t_2$ is the difference in its position at $t_1$ and $t_2$:

$$\Delta \mathbf{r}\stackrel{\text{def}}{=}\mathbf{r}(t_2)-\mathbf{r}(t_1)$$