What is path length? What is displacement?

(N/A) Path length is the total distance covered by an object during its motion between two points. It is a scalar quantity,meaning it has magnitude but no direction.
Displacement is the change in the position of an object in a particular interval of time. It is defined as the difference between the final position $(x_2)$ and the initial position $(x_1)$: $\Delta x = x_2 - x_1$. Displacement is a vector quantity,as it has both magnitude and direction.
Example: Consider a car moving from origin $O$ $(x=0)$ to point $P$ $(x=360 \ m)$ and then back to point $Q$ $(x=240 \ m)$.
$1$. Path length: The total distance covered is $OP + PQ = 360 \ m + (360 \ m - 240 \ m) = 360 \ m + 120 \ m = 480 \ m$.
$2$. Displacement: The displacement is the final position minus the initial position: $\Delta x = x_Q - x_O = 240 \ m - 0 \ m = +240 \ m$. The positive sign indicates the direction is along the positive $x$-axis.