The scientific definition of distance describes the length of a line between two points, or how far apart two objects are. The scalar measurement uses the curved line of the path between two locations as opposed to a vector, or straight line which begins and ends with '0.'
Distance is the scalar measurement of a length or interval between two points and is measured by considering the complete path that it takes to get from one point to another. Displacement is the vector measure of an interval between two locations and describes the shortest path connecting them.
The actual or scalar measure is what is described as the scientific definition of distance. For example, consider an example in which a man walks from his house to his car and back. The path he traveled to get from his house to his car and back is his 'path.' The scalar measurement of the interval or length of the path is the total distance he walked from his car, to his house, and back to his car. The vector measurement, which describes how far he travelled from the beginning to the end of his path, would be zero, because he returned to the original starting point and the displacement did not change.