The ideal gas law assumes that there is no interaction between gas molecules, that electrostatic energies between them do not exist, and that the presence of each molecule does not interfere with the other. This assumption can be made at low temperatures and low pressures, since the energy of the molecules is low and they are far from each other.
In reality, that is to say a real gas, if the molecules interfere with each other, the movement of the molecules can cause shocks between them, collisions and transfer of energy, attractions or repulsions. The higher the temperature, the higher the energy of each molecule, and if we have a higher pressure, the molecules will be closer to each other, so the probability of interaction between them grows and the behavior of the gas will not be very different to that of an ideal gas.