Question

why is the atucal distance on the ground reduced on the map​

Answer 1

Answer:

in short, it allows you to make measurements in the map and convert them to real distances.

More importantly, it allows you to understand how the map was drawn: a larger scale map, in which things are larger, has been drawn more carefully or with better precision that a small scale map, in which things are less detailed.

For example, if the map says something like 1:500.000, this means that 1 cm in the map is the same as 500,000 cm or 5.000 meters in real life.

It also may say something like 1 cm = 5 kilometers