In this case, rugs are classified as
moisture -proof, which not only can tolerate moisture without any special consequences, but also quickly return to working condition. For example, a plastic or aluminium product can be simply wiped off; but the fabric is considered waterproof only if it has a high density and/or a special impregnation that prevents it from getting wet.
It is also worth noting that for many formally “waterproof” models, intense exposure to moisture is still undesirable: for example, an inexpensive plastic mat that is not wiped off in time can delaminate. And at the same time, on the contrary: many fabric models that are not moisture resistant can be washed and even washed without consequences (they will only dry for quite a long time).