PA+ provides some UVA protection with a factor of PPD 2-4. It protects sensitive skin against low to medium UV radiation.
PA++ provides moderate UVA protection with a factor of PPD 4-8. It offers better protection from UVA rays and can be used by people with normal skin exposed to medium UV radiation.
PA+++ provides good UVA protection with a factor of PPD > 8. It is the strongest grade of UVA protection now available. It is designed for normal skin under very strong or direct UV radiation. (Source: PA+++)