Question

importance of latitudes and longitudes

Answer 1

Latitude
Horizontal mapping lines on Earth are lines of latitude. They are known as "parallels" of latitude, because they run parallel to the equator. One simple way to visualize this might be to think about having imaginary horizontal "hula hoops" around the earth, with the biggest hoop around the equator, and then progressively smaller ones stacked above and below it to reach the North and South Poles.
Longitude
Vertical mapping lines on Earth are lines of longitude, known as "meridians". One simple way to visualize this might be to think about having hula hoops cut in half, vertically positioned with one end at the North Pole and the other at the South Pole.

Answer 2

1) Latitudes and longitudes are used for pinpointing the exact location on both map and globe. 
2) They are very helpful to calculate time. 
3) They are used to define the climates over the tropics.