The correct pressure to be applied should always respect the minimum and maximum values advised by the tyre producer.
Besides, it is directly related to the rider’s intended use, weight and goals. So, the adequate pressure depends on the rider’s handling, the type of ground and track, as well as the comfort he’s looking for.
Please note that, the higher the pressure, the more protected the rim will be, and the less friction will there be with the floor/ track, thus, allowing a smoother rolling. On the other hand, a lower pressure gives a better grip, ideal for irregular ground, however, with more cycling resistance and lower absorption of impacts from the tyre.