Why scientists care
Gas laws connect pressure, volume, temperature and amount of substance. The ideal-gas equation PV = nRT is a powerful model whose accuracy depends on conditions.
Real gases approach ideal behaviour most closely when intermolecular effects and molecular volume are relatively unimportant.
A concrete example
At fixed volume and amount, doubling absolute temperature in the ideal model doubles pressure.
Try to notice
Science becomes memorable when a definition is connected to something measurable or observable.