Question

Why do we draw imaginary lines on the globe/ map?

Answer 1

The imaginary lines called parallels of latitudes and meridian of longitudes is merely for identification of where things are on a map or a globe. By these lines the distances are measured in degrees.

Answer 2

The imaginary line around the globe are very important because are drawn for navigation and geographic information. These lines are helpful in determining location of an object around the globe. Distances of the objects are also found due to these lines.
The equator is very important because it determines seasons with respect to sun position.