This manuscript aims at summarising the different physical properties involved in lightning discharges in thunderclouds. As well as to present the different techniques to observe the electromagnetic characteristics emitted by the lightning discharge, a concise overview is given of the different European networks committed to lightning observations. Finally, we outline various scientific studies that can be executed with the observed lightning properties. As such, we hope to provide the reader with a brief understanding of the different aspects associated with lightning studies. We conclude with some future prospects of the lightning studies at the Royal Meteorological Institute of Belgium (RMI)