Concealed
Source Player Core pg. 426
A concealed creature is in mist, within dim light, or amid something else that obscures sight but isn't a physical barrier. When you target a creature that's concealed from you, you must attempt a DC 5 flat check (in the sidebar) before you roll to determine your effect. If you fail, you don't affect the target. The concealed condition doesn't change which of the main categories of detection apply. A creature in a light fog bank is still observed even though it's concealed.