Gamma-ray bursts (GRBs) are the most luminous and explosive transient phenomena in the universe after the Big Bang. A powerful tool for characterizing and classifying GRBs to allow them to be used as tracers of the expansion history of the universe and to understand their mysterious and debated physical mechanisms has been recently presented by an international team of researchers led by Dr. Maria Dainotti, assistant professor at Jagiellonian University, Poland. The new article, which has been accepted by the Astrophysical Journal, is a statistical analysis of the properties of the mysterious GRBs, aimed at determining the observational properties of GRB subclasses. The article pays particular attention to the GRBs associated with kilonovae.