The ideal gas law makes some assumptions about gases that are not necessarily true. This means that the ideal gas law has some limitations.
For example, the ideal gas law makes an assumption that gas particles have no volume and are not attracted to each other.
Here's why the idea gas law has limitations.
Imagine that you condense an ideal gas. Since the particles of an ideal gas have no volume, a gas should be able to be condensed to a volume of zero. Reality check: Real gas particles occupy space. A gas will be condensed to form a liquid which has volume. The gas law no longer applies because the substance is no longer a gas!
Same scenario. We assume that gas particles are not attracted to each other. Reality check: Real gas particles are attracted to each other. As kinetic energy decreases as a gas is cooled, the particles will eventually move slowly enough that there attractive forces cause them to condense. The gas law no longer applies because the substance is no longer a gas!