Lightning is a severe weather phenomenon where an electrical charge that has been formed inside a thunder cloud is released in the form of a flash of light. A lightning can either hit another cloud or the ground. 

During thunder and lightning storms, we often experience rain and heavy winds. The bolts of lightning that hit the ground can cause damage to trees, people and electrical equipment. Lightning tends to target tall objects, such as trees and tall buildings. 

The sound of thunder can be heard for tens of kilometres, and the lightning can be seen even further away than that. 

Why does the sound of thunder always arrive only after the flash of lightning? This happens because sound travels more slowly than light. You can use this to measure the distance between yourself and the thunderstorm. If the lightning and the sound of thunder are separated by three seconds, the thunderstorm is located one kilometre from you.