Question

On a map i am shown by thick dashes and dots?? Who am i?

Answer 1

The international or national boundaries between two countries or two states or two cities are represented by thick dashes and dot.

Answer 2

A map is generally a drawing or a plan of the 'surface of the earth' or the 'world'.

EXPLANATION:

Maps are the most ancient and accurate form of representation of the earth, a map can be of a county or a place, with the right sense of direction a map is a 'good guide'.

On a world map the thick dashes and the dots represent  the international boundaries and the borders of countries.