The displacement of a particle is defined as its change in position. If a particle is moving, we can easily determine its change in position. To collect the data of a body in motion, the basic information we need before going into deep is the displacement from initial to final position. As it moves from
an initial position $x_i$ to a final position $x_f$, its displacement is given by the Greek letter delta $(\Delta)$ to denote the change in a quantity. Therefore, we
write the displacement, or change in position, of the particle as;
$$ \Delta x = x_f - x_i $$
What is the difference between Displacement and Distance
In physics, distance and displacement are used to indicate the length between two points.
However, these two are not one and the same thing. While distance
is the length of the actual path between two locations
, on the other hand, is the length of the shortest path between two locations
Fig. No.1 Difference Between Distance and Displacement.
So, the distance tells us, how much path is traveled by the body, during motion and the displacement gives us an idea of how far the body is from its starting point, and in which direction.
Displacement is a vector while Distance is an example of a scalar quantity.